Refrigeration cycle apparatus and refrigeration cycle system

ABSTRACT

A refrigeration cycle apparatus includes a refrigerant circuit configured to circulate refrigerant, a heat exchanger unit accommodating a heat exchanger of the refrigerant circuit, and a controller configured to control the heat exchanger unit. The heat exchanger unit includes an air-sending fan, an electric refrigerant detection unit, and a notifier configured to output notification of an abnormality. The controller is configured to stop electric supply to the electric refrigerant detection unit when an electric supply stop condition is satisfied under a state in which the electric refrigerant detection unit is supplied with electricity, supply electricity to the electric refrigerant detection unit when an electric supply condition is satisfied under a state in which the electric supply to the electric refrigerant detection unit is stopped, and cause the notifier to output the notification of the abnormality when an integrated time of electric supply to the electric refrigerant detection unit becomes equal to or larger than a threshold time.

TECHNICAL FIELD

The present invention relates to a refrigeration cycle apparatus and arefrigeration cycle system that include a refrigerant detection unit.

BACKGROUND ART

In Patent Literature 1, there is disclosed an air-conditioningapparatus. The air-conditioning apparatus includes a gas sensor providedon an outer surface of an indoor unit and configured to detectrefrigerant, and a controller configured to control an indoorair-sending fan to rotate when the gas sensor detects the refrigerant.The air-conditioning apparatus can detect leaked refrigerant by the gassensor when the refrigerant leaks to an indoor space through anextension pipe connected to the indoor unit or when refrigerant leakedinside the indoor unit passes through a gap of a casing of the indoorunit to flow outside of the indoor unit. Further, the indoor air-sendingfan is rotated when the leakage of the refrigerant is detected so thatindoor air is sucked through an air inlet formed in the casing of theindoor unit and air is blown off to the indoor space through an airoutlet. In this manner, the leaked refrigerant can be diffused.

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent No. 4599699

SUMMARY OF INVENTION Technical Problem

When an electric supply gas sensor, for example, a semiconductor gassensor that serves as a refrigerant detection unit, in an electricitysupplied state, is exposed to a gas to be detected or miscellaneousgases other than the gas to be detected for a long period of time, thedetection characteristics may be changed. When the electric supply gassensor whose detection characteristics have been changed is kept incontinuous use, there has been a problem of a risk of delay in detectionof leakage of refrigerant when the leakage occurs or false detection inwhich leakage is detected when the refrigerant has not leaked. Inparticular, when the above-mentioned delay in detection of leakageoccurs, the indoor air-sending fan cannot be rotated even when therefrigerant has leaked, and hence there is a risk that the indoorrefrigerant concentration may be locally increased.

The present invention has been made to solve the above-mentionedproblems, and has an object to provide a refrigeration cycle apparatusand a refrigeration cycle system that are capable of preventing arefrigerant detection unit whose detection characteristics have beenchanged from being kept in continuous use.

Solution to Problem

According to one embodiment of the present invention, there is provideda refrigeration cycle apparatus including a refrigerant circuitconfigured to circulate refrigerant, a heat exchanger unit accommodatinga heat exchanger of the refrigerant circuit, and a controller configuredto control the heat exchanger unit. The heat exchanger unit includes anair-sending fan, an electric refrigerant detection unit, and a notifierconfigured to output notification of an abnormality. The controller isconfigured to stop electric supply to the electric refrigerant detectionunit when an electric supply stop condition is satisfied under a statein which the electric refrigerant detection unit is supplied withelectricity, supply electricity to the electric refrigerant detectionunit when an electric supply condition is satisfied under a state inwhich the electric supply to the electric refrigerant detection unit isstopped, and cause the notifier to output the notification of theabnormality when an integrated time of electric supply to the electricrefrigerant detection unit becomes equal to or larger than a firstthreshold time.

According to one embodiment of the present invention, there is provideda refrigeration cycle system including a refrigeration cycle apparatusincluding a refrigerant circuit configured to circulate refrigerant, acontroller configured to control the refrigerant circuit, and a notifierconfigured to output notification of an abnormality, and an electricrefrigerant detection unit, the electric refrigerant detection unitbeing configured to output a detection signal to the controller. Thecontroller is configured to stop electric supply to the electricrefrigerant detection unit when an electric supply stop condition issatisfied under a state in which the electric refrigerant detection unitis supplied with electricity, supply electricity to the electricrefrigerant detection unit when an electric supply condition issatisfied under a state in which the electric supply to the electricrefrigerant detection unit is stopped, and cause the notifier to outputthe notification of the abnormality when an integrated time of electricsupply to the electric refrigerant detection unit becomes equal to orlarger than a first threshold time.

Advantageous Effects of Invention

According to one embodiment of the present invention, the notifieroutputs the notification of the abnormality when the integrated time ofelectric supply to the refrigerant detection unit becomes equal to orlarger than the threshold time, and hence the refrigerant detection unitwhose detection characteristics have been changed can be prevented frombeing kept in continuous use.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a refrigerant circuit diagram for illustrating a schematicconfiguration of an air-conditioning apparatus according to a firstembodiment of the present invention.

FIG. 2 is a front view for illustrating a configuration of an outerappearance of an indoor unit 1 of the air-conditioning apparatusaccording to the first embodiment of the present invention.

FIG. 3 is a front view for schematically illustrating an internalstructure of the indoor unit 1 of the air-conditioning apparatusaccording to the first embodiment of the present invention.

FIG. 4 is a side view for schematically illustrating the internalstructure of the indoor unit 1 of the air-conditioning apparatusaccording to the first embodiment of the present invention.

FIG. 5 is a flowchart for illustrating an example of refrigerant leakagedetection processing executed by a controller 30 of the air-conditioningapparatus according to the first embodiment of the present invention.

FIG. 6 is a state transition diagram for illustrating an example of astate transition of the air-conditioning apparatus according to thefirst embodiment of the present invention.

FIG. 7 is a block diagram for illustrating an example of a configurationof the controller 30 of the air-conditioning apparatus according to thefirst embodiment of the present invention.

FIG. 8 is a graph for showing a relationship between a rotation speed ofan indoor air-sending fan 7 f and an air-conditioning apparatus state inan air-conditioning apparatus according to a second embodiment of thepresent invention.

FIG. 9 is a diagram for schematically illustrating a configuration of anoutdoor unit 2 of an air-conditioning apparatus according to a fourthembodiment of the present invention.

FIG. 10 is a diagram for schematically illustrating an overallconfiguration of a refrigeration cycle system according to a fifthembodiment of the present invention.

FIG. 11 is a block diagram for illustrating a configuration of acontroller 30 of the refrigeration cycle system according to the fifthembodiment of the present invention.

DESCRIPTION OF EMBODIMENTS First Embodiment

A refrigeration cycle apparatus according to a first embodiment of thepresent invention is described. In the first embodiment, anair-conditioning apparatus is exemplified as the refrigeration cycleapparatus. FIG. 1 is a refrigerant circuit diagram for illustrating aschematic configuration of the air-conditioning apparatus according tothe first embodiment. In FIG. 1 and the subsequent figures, componentsmay have a dimensional relationship, shapes, and other aspects that aredifferent from actual ones.

As illustrated in FIG. 1, the air-conditioning apparatus includes arefrigerant circuit 40 configured to circulate refrigerant. Therefrigerant circuit 40 includes a compressor 3, a refrigerant flowswitching device 4, a heat source-side heat exchanger 5 (for example,outdoor heat exchanger), a pressure reducing device 6, and a load-sideheat exchanger 7 (for example, indoor heat exchanger), which areannularly connected in order through refrigerant pipes. Further, theair-conditioning apparatus includes an outdoor unit 2, which isinstalled, for example, outdoors as a heat source unit. Further, theair-conditioning apparatus includes an indoor unit 1 (example of a heatexchanger unit), which is installed, for example, indoors as a loadunit. The indoor unit 1 and the outdoor unit 2 are connected to eachother through extension pipes 10 a and 10 b forming parts of therefrigerant pipes.

Examples of a refrigerant used as the refrigerant to be circulated bythe refrigerant circuit 40 include a slightly flammable refrigerant,such as HFO-1234yf and HFO-1234ze and a strongly flammable refrigerant,such as R290 and R1270. These refrigerants may be each used as a singlecomponent refrigerant, or may be used as a mixed refrigerant obtained bymixing two or more kinds of the refrigerants with each other. In thefollowing description, the refrigerant having a flammability equal to orhigher than a slightly flammable level (for example, 2 L or higher incategory of ASHRAE 34) is sometimes referred to as “flammablerefrigerant”. Further, as the refrigerant to be circulated by therefrigerant circuit 40, a nonflammable refrigerant, such as R22 andR410A, having a nonflammability (for example, 1 in category of ASHRAE34) can be used. These refrigerants have a density larger than that ofair under, for example, an atmospheric pressure.

The compressor 3 is a fluid machine configured to compress suckedlow-pressure refrigerant and to discharge the refrigerant ashigh-pressure refrigerant. The refrigerant flow switching device 4 isconfigured to switch a flow direction of the refrigerant in therefrigerant circuit 40 between a cooling operation time and a heatingoperation time. As the refrigerant flow switching device 4, for example,a four-way valve is used. The heat source-side heat exchanger 5 is aheat exchanger configured to act as a radiator (for example, condenser)at the cooling operation time and to act as an evaporator at the heatingoperation time. In the heat source-side heat exchanger 5, heat isexchanged between the refrigerant circulated through an inside of theheat source-side heat exchanger 5 and outdoor air sent by an outdoorair-sending fan 5 f described later. The pressure reducing device 6 isconfigured to reduce the pressure of the high-pressure refrigerant sothat the high-pressure refrigerant becomes the low-pressure refrigerant.As the pressure reducing device 6, for example, an electronic expansionvalve capable of adjusting its opening degree is used. The load-sideheat exchanger 7 is a heat exchanger configured to act as an evaporatorat the cooling operation time and to act as a radiator (for example,condenser) at the heating operation time. In the load-side heatexchanger 7, heat is exchanged between the refrigerant circulatedthrough an inside of the load-side heat exchanger 7 and air sent by anindoor air-sending fan 7 f described later. In this case, the coolingoperation represents an operation for supplying low-temperature andlow-pressure refrigerant to the load-side heat exchanger 7, and theheating operation represents an operation for supplying high-temperatureand high-pressure refrigerant to the load-side heat exchanger 7.

The outdoor unit 2 accommodates the compressor 3, the refrigerant flowswitching device 4, the heat source-side heat exchanger 5, and thepressure reducing device 6. Further, the outdoor unit 2 accommodates theoutdoor air-sending fan 5 f configured to supply outdoor air to the heatsource-side heat exchanger 5. The outdoor air-sending fan 5 f isinstalled to be opposed to the heat source-side heat exchanger 5. Whenthe outdoor air-sending fan 5 f is rotated, an airflow passing throughthe heat source-side heat exchanger 5 is generated. As the outdoorair-sending fan 5 f, for example, a propeller fan is used. The outdoorair-sending fan 5 f is arranged, for example, downstream of the heatsource-side heat exchanger 5 along the airflow generated by the outdoorair-sending fan 5 f.

The refrigerant pipes arranged in the outdoor unit 2 include arefrigerant pipe connecting between an extension pipe connection valve13 a on the gas side at the cooling operation time and the refrigerantflow switching device 4, a suction pipe 11 connected to a suction sideof the compressor 3, a discharge pipe 12 connected to a discharge sideof the compressor 3, a refrigerant pipe connecting between therefrigerant flow switching device 4 and the heat source-side heatexchanger 5, a refrigerant pipe connecting between the heat source-sideheat exchanger 5 and the pressure reducing device 6, and a refrigerantpipe connecting between an extension pipe connection valve 13 b on theliquid side at the cooling operation time and the pressure reducingdevice 6. The extension pipe connection valve 13 a is formed of atwo-way valve capable of switching between open and close, and has oneend to which a flare joint is mounted. Further, the extension pipeconnection valve 13 b is formed of a three-way valve capable ofswitching between open and close. The extension pipe connection valve 13b has one end to which a service port 14 a is mounted, and another endto which a flare joint is mounted. The service port 14 a is used at atime of vacuuming, which is a preliminary work of filling therefrigerant circuit 40 with refrigerant.

At both the cooling operation time and the heating operation time,high-temperature and high-pressure gas refrigerant compressed by thecompressor 3 flows through the discharge pipe 12. At both the coolingoperation time and the heating operation time, low-temperature andlow-pressure gas refrigerant or two-phase refrigerant subjected to anevaporation action flows through the suction pipe 11. The suction pipe11 is connected to a low-pressure-side service port 14 b with a flarejoint, and the discharge pipe 12 is connected to a high-pressure-sideservice port 14 c with a flare joint. The service ports 14 b and 14 care used to connect a pressure gauge to measure the operating pressureat a time of installation of the air-conditioning apparatus or at a timeof a trial run for a repair.

The indoor unit 1 accommodates the load-side heat exchanger 7. Further,the indoor air-sending fan 7 f configured to supply air to the load-sideheat exchanger 7 is installed in the indoor unit 1. When the indoorair-sending fan 7 f is rotated, an airflow passing through the load-sideheat exchanger 7 is generated. As the indoor air-sending fan 7 f, acentrifugal fan (for example, sirocco fan or turbofan), a cross flowfan, a mixed flow fan, an axial fan (for example, propeller fan), orother fans is used depending on a configuration of the indoor unit 1.The indoor air-sending fan 7 f of the first embodiment is arrangedupstream of the load-side heat exchanger 7 along the airflow generatedby the indoor air-sending fan 7 f, but may be arranged downstream of theload-side heat exchanger 7.

Of the refrigerant pipes of the indoor unit 1, a gas-side indoor pipe 9a is provided in a connection portion to the gas-side extension pipe 10a with a joint portion 15 a (for example, flare joint) for connection tothe extension pipe 10 a. Further, of the refrigerant pipes of the indoorunit 1, a liquid-side indoor pipe 9 b is provided in a connectionportion to the liquid-side extension pipe 10 b with a joint portion 15 b(for example, flare joint) for connection to the extension pipe 10 b.

Further, the indoor unit 1 includes a suction air temperature sensor 91configured to measure a temperature of indoor air sucked from theindoors, a heat exchanger entrance temperature sensor 92 configured tomeasure a refrigerant temperature in a cooling operation time entranceportion (heating operation time exit portion) of the load-side heatexchanger 7, and a heat exchanger temperature sensor 93 configured tomeasure a refrigerant temperature (evaporating temperature or condensingtemperature) of a two-phase portion of the load-side heat exchanger 7.In addition, the indoor unit 1 includes a refrigerant detection unit 99(for example, semiconductor gas sensor) described later. These sensorsare configured to output a detection signal to a controller 30configured to control an entirety of the indoor unit 1 or theair-conditioning apparatus.

The controller 30 includes a microcomputer including a CPU, a ROM, aRAM, an input-output port, and a timer. The controller 30 can conductdata communications with an operation unit 26 (see FIG. 2). Theoperation unit 26 is configured to receive an operation performed by auser to output an operation signal based on the operation to thecontroller 30. The controller 30 of the first embodiment is configuredto control the operation of the entirety of the indoor unit 1 or theair-conditioning apparatus including an operation of the indoorair-sending fan 7 f on the basis of an operation signal received fromthe operation unit 26, the detection signal received from the sensors,or other signals. Further, the controller 30 of the first embodiment canconduct switching between electric supply and non-electric supply to therefrigerant detection unit 99. The controller 30 may be provided insidea casing of the indoor unit 1, or may be provided inside a casing of theoutdoor unit 2. Further, the controller 30 may include an outdoor unitcontroller provided to the outdoor unit 2 and an indoor unit controllerthat is provided to the indoor unit 1 and capable of conducting datacommunications with the outdoor unit controller.

Next, a description is made of the operation of the refrigerant circuit40 of the air-conditioning apparatus. First, the operation at thecooling operation time is described. In FIG. 1, the solid arrowsindicate flow directions of the refrigerant at the cooling operationtime. The refrigerant circuit 40 is configured such that, in the coolingoperation, a refrigerant flow passage is switched by the refrigerantflow switching device 4 as indicated by the solid line, and thelow-temperature and low-pressure refrigerant flows into the load-sideheat exchanger 7.

The high-temperature and high-pressure gas refrigerant discharged fromthe compressor 3 first flows into the heat source-side heat exchanger 5after passing through the refrigerant flow switching device 4. In thecooling operation, the heat source-side heat exchanger 5 acts as acondenser. That is, in the heat source-side heat exchanger 5, heat isexchanged between the refrigerant circulated through the inside and theoutdoor air sent by the outdoor air-sending fan 5 f, and heat ofcondensation of the refrigerant is transferred to the outdoor air. Withthis operation, the refrigerant that has flowed into the heatsource-side heat exchanger 5 is condensed to become high-pressure liquidrefrigerant. The high-pressure liquid refrigerant flows into thepressure reducing device 6, and has the pressure reduced to becomelow-pressure two-phase refrigerant. The low-pressure two-phaserefrigerant passes through the extension pipe 10 b, and flows into theload-side heat exchanger 7 of the indoor unit 1. In the coolingoperation, the load-side heat exchanger 7 acts as an evaporator. Thatis, in the load-side heat exchanger 7, heat is exchanged between therefrigerant circulated through the inside and the air (for example,indoor air) sent by the indoor air-sending fan 7 f, and heat ofevaporation of the refrigerant is received from the sent air. With thisoperation, the refrigerant that has flowed into the load-side heatexchanger 7 evaporates to become low-pressure gas refrigerant ortwo-phase refrigerant. Further, the air sent by the indoor air-sendingfan 7 f is cooled by a heat receiving action of the refrigerant. Thelow-pressure gas refrigerant or two-phase refrigerant evaporated by theload-side heat exchanger 7 passes through the extension pipe 10 a andthe refrigerant flow switching device 4, and is sucked by the compressor3. The refrigerant sucked by the compressor 3 is compressed to becomethe high-temperature and high-pressure gas refrigerant. In the coolingoperation, the above-mentioned cycle is repeated.

Next, the operation at the heating operation time is described. In FIG.1, the dotted arrows indicate flow directions of the refrigerant at theheating operation time. The refrigerant circuit 40 is configured suchthat, in the heating operation, the refrigerant flow passage is switchedby the refrigerant flow switching device 4 as indicated by the dottedline, and the high-temperature and high-pressure refrigerant flows intothe load-side heat exchanger 7. At the heating operation time, therefrigerant flows in a direction reverse to that of the coolingoperation time, and the load-side heat exchanger 7 acts as a condenser.That is, in the load-side heat exchanger 7, heat is exchanged betweenthe refrigerant circulated through the inside and the air sent by theindoor air-sending fan 7 f, and the heat of condensation of therefrigerant is transferred to the sent air. With this operation, the airsent by the indoor air-sending fan 7 f is heated by a heat transferringaction of the refrigerant.

FIG. 2 is a front view for illustrating a configuration of an outerappearance of the indoor unit 1 of the air-conditioning apparatusaccording to the first embodiment. FIG. 3 is a front view forschematically illustrating an internal structure of the indoor unit 1.FIG. 4 is a side view for schematically illustrating the internalstructure of the indoor unit 1. The left of FIG. 4 indicates a frontsurface side (indoor space side) of the indoor unit 1. In the firstembodiment, as the indoor unit 1, the indoor unit 1 of a floor type,which is installed on a floor surface of an indoor space that is anair-conditioned space, is described as an example. In the followingdescription, positional relationships (for example, top-bottomrelationship) between components are, in principle, exhibited when theindoor unit 1 is installed in a usable state.

As illustrated in FIG. 2 to FIG. 4, the indoor unit 1 includes a casing111 having an upright rectangular parallelepiped shape. An air inlet 112configured to suck air inside the indoor space is formed in a lowerportion of a front surface of the casing 111. The air inlet 112 of thefirst embodiment is provided in a position proximate to the floorsurface and below a center portion of the casing 111 along a verticaldirection. An air outlet 113 configured to blow off the air sucked fromthe air inlet 112 indoors is formed in the upper portion of the frontsurface of the casing 111, that is, in a position higher than the airinlet 112 (for example, above the center portion of the casing 111 alongthe vertical direction). The operation unit 26 is provided to the frontsurface of the casing 111, above the air inlet 112, and below the airoutlet 113. The operation unit 26 is connected to the controller 30through a communication line, and is capable of conducting mutual datacommunications with the controller 30. In the operation unit 26, anoperation start operation, an operation end operation, switching of anoperation mode, setting of a set temperature and a set airflow rate, andother operations are conducted for the air-conditioning apparatus inaccordance with user's operations. The operation unit 26 includes adisplay unit or an audio output unit as a notifier configured to outputthe notification of information.

The casing 111 is a hollow box body, and a front opening part is formedon a front surface of the casing 111. The casing 111 includes a firstfront panel 114 a, a second front panel 114 b, and a third front panel114 c, which are removably mounted to the front opening part. The firstfront panel 114 a, the second front panel 114 b, and the third frontpanel 114 c all have a substantially rectangular flat outer shape. Thefirst front panel 114 a is removably mounted to a lower part of thefront opening part of the casing 111. In the first front panel 114 a,the air inlet 112 described above is formed. The second front panel 114b is arranged immediately above the first front panel 114 a, and isremovably mounted to a center part of the front opening part of thecasing 111 along the vertical direction. In the second front panel 114b, the operation unit 26 described above is provided. The third frontpanel 114 c is arranged immediately above the second front panel 114 b,and is removably mounted to an upper part of the front opening part ofthe casing 111. In the third front panel 114 c, the air outlet 113described above is formed.

An internal space of the casing 111 is roughly divided into a space 115a being an air-sending part and a space 115 b being a heat-exchangingpart located above the space 115 a. The space 115 a and the space 115 bare partitioned by a partition portion 20. The partition portion 20 has,for example, a flat shape, and is arranged approximately horizontally.In the partition portion 20, at least an air passage opening part 20 ais formed to serve as an air passage between the space 115 a and thespace 115 b. The space 115 a is defined to be exposed to the frontsurface side when the first front panel 114 a is removed from the casing111, and the space 115 b is defined to be exposed to the front surfaceside when the second front panel 114 b and the third front panel 114 care removed from the casing 111. That is, the partition portion 20 ismounted at approximately the same height as a height of an upper edge ofthe first front panel 114 a or a lower edge of the second front panel114 b. In this case, the partition portion 20 may be formed integrallywith a fan casing 108 described later, may be formed integrally with adrain pan described later, or may be formed separately from the fancasing 108 or the drain pan.

In the space 115 a, the indoor air-sending fan 7 f, which is configuredto cause a flow of air from the air inlet 112 to the air outlet 113 inthe air passage 81 of the casing 111, is arranged. The indoorair-sending fan 7 f of the first embodiment is a sirocco fan including amotor (not shown) and an impeller 107 that is connected to an outputshaft of the motor and has a plurality of blades arranged, for example,at regular intervals along a circumferential direction. A rotary shaftof the impeller 107 is arranged substantially in parallel with a depthdirection of the casing 111. The rotation speed of the indoorair-sending fan 7 f is controlled by the controller 30 on the basis of aset airflow rate or other conditions set by the user to be variably setat multiple stages (for example, two stages or more) or continuously.

The impeller 107 of the indoor air-sending fan 7 f is covered with thefan casing 108 having a spiral shape. The fan casing 108 is formed, forexample, separately from the casing 111. A suction opening part 108 bfor sucking the indoor air through the air inlet 112 into the fan casing108 is formed close to the center of a spiral of the fan casing 108. Thesuction opening part 108 b is located to be opposed to the air inlet112. Further, an air outlet opening part 108 a for blowing off the sentair is formed along a direction of a tangential line of the spiral ofthe fan casing 108. The air outlet opening part 108 a is located to bedirected upward, and is connected to the space 115 b through the airpassage opening part 20 a of the partition portion 20. In other words,the air outlet opening part 108 a communicates to the space 115 bthrough the air passage opening part 20 a. An opening end of the airoutlet opening part 108 a and an opening end of the air passage openingpart 20 a may be directly linked to each other, or may be indirectlylinked to each other through a duct member or other members.

Further, in the space 115 a, there is provided an electric component box25 accommodating, for example, a microcomputer that forms the controller30, different kinds of electrical components, and a substrate.

The load-side heat exchanger 7 is arranged in the air passage 81 in thespace 115 b. The drain pan (not shown) configured to receive condensedwater that is condensed on a surface of the load-side heat exchanger 7is provided below the load-side heat exchanger 7. The drain pan may beformed as a part of the partition portion 20, or may be formedseparately from the partition portion 20 to be arranged on the partitionportion 20.

The refrigerant detection unit 99 is provided in a position close to andbelow the space 115 a. As the refrigerant detection unit 99, an electricsupply-type refrigerant detection unit including an electric supply gassensor, for example, a semiconductor gas sensor or a hot-wire typesemiconductor gas sensor, is used. The refrigerant detection unit 99 isconfigured to detect, for example, a refrigerant concentration in theair around the refrigerant detection unit 99, and to output thedetection signal to the controller 30. The controller 30 determinespresence or absence of leakage of the refrigerant on the basis of thedetection signal received from the refrigerant detection unit 99.

In the indoor unit 1, a brazed portion of the load-side heat exchanger 7and the joint portions 15 a and 15 b are liable to leak the refrigerant.Further, the refrigerant used in the first embodiment has a densitylarger than that of the air under the atmospheric pressure. Hence, therefrigerant detection unit 99 of the first embodiment is provided in aposition lower in height than the load-side heat exchanger 7 and thejoint portions 15 a and 15 b in the casing 111. With this arrangement,the refrigerant detection unit 99 can reliably detect the leakedrefrigerant at least when the indoor air-sending fan 7 f is stopped. Inthe first embodiment, the refrigerant detection unit 99 is provided in alower part of the space 115 a, but an arrangement position of therefrigerant detection unit 99 may be another position.

FIG. 5 is a flowchart for illustrating an example of the flow of therefrigerant leakage detection processing executed by the controller 30of the air-conditioning apparatus according to the first embodiment. Therefrigerant leakage detection processing is executed repeatedly with apredetermined time interval at normal time including time when theair-conditioning apparatus is operating and is stopped, only time whenthe air-conditioning apparatus is stopped, or only time when theair-conditioning apparatus is in a normal state A described later.

In Step S1 of FIG. 5, the controller 30 acquires information on therefrigerant concentration around the refrigerant detection unit 99 onthe basis of the detection signal received from the refrigerantdetection unit 99.

Next, in Step S2, the controller 30 determines whether or not therefrigerant concentration around the refrigerant detection unit 99 isequal to or larger than a threshold value set in advance. When thecontroller 30 determines that the refrigerant concentration is equal toor larger than the threshold value, the procedure advances to Step S3,and when the refrigerant concentration is smaller than the thresholdvalue, the processing is brought to an end.

In Step S3, the controller 30 starts the operation of the indoorair-sending fan 7 f. When the indoor air-sending fan 7 f is alreadyoperating, the operation is continued as it is. Further, in Step S3, therotation speed of the indoor air-sending fan 7 f may be set to arotation speed at which the refrigerant can be sufficiently diffusedeven when the refrigerant leakage amount is maximum (for example,rotation speed that is equal to or larger than a threshold value R1described later). The rotation speed is not limited to the rotationspeed used during a normal operation. In Step S3, the notifier (forexample, display unit or audio output unit) provided in the operationunit 26 may be used to output the notification that the leakage of therefrigerant has occurred. Further, the indoor air-sending fan 7 f thathas started to operate in Step S3 may be stopped after a predeterminedtime set in advance has elapsed.

As described above, in the refrigerant leakage detection processing,when the leakage of the refrigerant is detected (that is, when therefrigerant concentration detected by the refrigerant detection unit 99is equal to or larger than the threshold value), the indoor air-sendingfan 7 f starts being operated. With this operation, it is possible todiffuse the leaked refrigerant. Hence, it is possible to inhibit therefrigerant concentration from increasing locally indoors.

As described above, in the first embodiment, examples of the refrigerantto be circulated by the refrigerant circuit 40 include flammablerefrigerants such as HFO-1234yf, HFO-1234ze, R290, and R1270.Consequently, if leakage of refrigerant occurs in the indoor unit 1,there is a fear that the indoor refrigerant concentration is increasedto form a flammable concentration region (for example, region in whichthe refrigerant concentration is equal to or larger than the lowerflammable limit (LFL)).

These flammable refrigerants have a density larger than that of airunder the atmospheric pressure. Consequently, when the leakage of therefrigerant occurs at a position at which the height from the floorsurface of the indoor space is relatively large, the leaked refrigerantis diffused while descending. Thus, the refrigerant concentrationbecomes uniform in the indoor space, and hence the refrigerantconcentration is less liable to be increased. In contrast, when theleakage of the refrigerant occurs at a position at which the height fromthe floor surface of the indoor space is small, the leaked refrigerantremains at a low position close to the floor surface, and hence therefrigerant concentration tends to be locally increased. As a result,the risk of the formation of the flammable concentration region isrelatively increased.

While the air-conditioning apparatus is operated, air is blown off tothe indoor space due to the operation of the indoor air-sending fan 7 fof the indoor unit 1. Consequently, even if the flammable refrigerantleaks to the indoor space, the leaked flammable refrigerant is diffusedin the indoor space by the air being blown off. In this manner, theflammable concentration region can be inhibited from being formed in theindoor space. However, while the air-conditioning apparatus is stopped,the indoor air-sending fan 7 f of the indoor unit 1 is also stopped, andhence the leaked refrigerant cannot be diffused by the air being blownoff. Consequently, detection of the leaked refrigerant is more requiredwhile the air-conditioning apparatus is stopped. In the firstembodiment, the operation of the indoor air-sending fan 7 f is startedwhen the leakage of the refrigerant is detected, and hence the flammableconcentration region can be inhibited from being formed in the indoorspace even when the flammable refrigerant leaks to the indoor spacewhile the air-conditioning apparatus is stopped.

FIG. 6 is a state transition diagram for illustrating an example of astate transition of the air-conditioning apparatus according to thefirst embodiment. As illustrated in FIG. 6, states of theair-conditioning apparatus include at least the normal state A, a normalstate B, and an end-of-life state of the refrigerant detection unit 99.Among these states, the normal state A and the normal state B are bothnormal states in which the leakage of the refrigerant has not occurred.The air-conditioning apparatus in the normal state A or the normal stateB conducts and stops the operation in the normal state in accordancewith the user's operation through the operation unit 26 or otheroperations. The state of the air-conditioning apparatus in the normalstate is controlled by the controller 30 on the basis of the rotationspeed of the indoor air-sending fan 7 f to mutually transition betweenthe normal state A and the normal state B. The threshold value R1 of therotation speed used for the determination of the state transitionbetween the normal state A and the normal state B is stored in advancein the ROM of the controller 30.

The end-of-life state of the refrigerant detection unit 99 among theabove-mentioned states is a state in which it is determined that therefrigerant detection unit 99 has come to its end of life on the basisof the time of electric supply to the refrigerant detection unit 99. Theend-of-life state of the refrigerant detection unit 99 is a state inwhich there is a risk of delay in detection of leakage of refrigerantwhen the leakage occurs. Hence, in the first embodiment, the end-of-lifestate of the refrigerant detection unit 99 is treated not as the normalstate but as one type of abnormal state. A threshold value H1 of thetime of electric supply, which is used for determination of a statetransition from the normal state to the end-of-life state of therefrigerant detection unit 99, is stored in advance in the ROM of thecontroller 30.

The stopped air-conditioning apparatus in which the indoor air-sendingfan 7 f is stopped is in the normal state A. In the normal state A, therefrigerant detection unit 99 is supplied with electricity throughcontrol of the controller 30. With this operation, the refrigerantdetection unit 99 enters an operation state in which the refrigerantdetection unit 99 can detect the refrigerant. That is, the normal stateA refers to a state in which the leakage of the refrigerant can bedetected by the refrigerant detection unit 99. Further, in the normalstate A, the timer included in the microcomputer of the controller 30 isused to integrate the time of electric supply to the refrigerantdetection unit 99 as an integrated time of electric supply. The initialvalue of the integrated time of electric supply is 0. The value of theintegrated time of electric supply is held even when power supply to theair-conditioning apparatus is interrupted. The integrated time ofelectric supply is prevented from being reset unless the refrigerantdetection unit 99 is replaced with a new unit.

When the operation of the air-conditioning apparatus is started inaccordance with the user's operation or other operations, the indoorair-sending fan 7 f is controlled by the controller 30 to rotate at apredetermined rotation speed. On condition that the rotation speed ofthe indoor air-sending fan 7 f becomes equal to or larger than thethreshold value R1 set in advance in the normal state A, the controller30 causes the state of the air-conditioning apparatus to transition fromthe normal state A to the normal state B. In the normal state B, theelectric supply to the refrigerant detection unit 99 is stopped throughthe control of the controller 30. With this operation, the refrigerantdetection unit 99 enters a stopped state in which the refrigerantdetection unit 99 cannot detect the refrigerant. That is, the normalstate B refers to a state in which the leakage of the refrigerant cannotbe detected by the refrigerant detection unit 99. Further, in the normalstate B, the integration of the time of electric supply to therefrigerant detection unit 99 is stopped.

On condition that the rotation speed of the indoor air-sending fan 7 fbecomes smaller than the threshold value R1 in the normal state B, thecontroller 30 causes the state of the air-conditioning apparatus totransition from the normal state B to the normal state A again. In thenormal state A, the electric supply to the refrigerant detection unit 99and the integration of the time of electric supply are restarted.

When the maximum rotation speed and the minimum rotation speed of theindoor air-sending fan 7 f are represented by Rmax and Rmin,respectively, the threshold value R1 is set, for example, within arotation speed range of 0 or more and Rmax or less (0≤R1≤Rmax),preferably within a rotation speed range of more than 0 and Rmax or less(0<R1≤Rmax), more preferably within a rotation speed range of more thanRmin and Rmax or less (Rmin<R1≤Rmax). In this case, the maximum rotationspeed Rmax is a maximum rotation speed as that of the indoor air-sendingfan 7 f or a motor of the indoor air-sending fan 7 f. The rotation speedof the indoor air-sending fan 7 f during the normal operation is set tobe equal to or smaller than the maximum rotation speed Rmax. That is,the maximum rotation speed of the indoor air-sending fan 7 f during thenormal operation is equal to or smaller than the maximum rotation speedRmax. When a flammable refrigerant is used, the threshold value R1 isdesired to be set to be equal to or larger than a rotation speed thatinhibits the flammable concentration region from being formed in theindoor space even when the maximum amount of refrigerant leaks to theindoor space. The threshold value R1 is set such that the controltolerance is taken into consideration. Further, when the rotation speedof the indoor air-sending fan 7 f varies due to the load of the motor,the threshold value R1 is set such that the maximum load is taken intoconsideration.

In the normal states (for example, normal state A) described above, whenthe integrated time of electric supply to the refrigerant detection unit99 becomes equal to or larger than the threshold value H1, for example,the controller 30 determines that the refrigerant detection unit 99 hascome to its end of life, and causes the state of the air-conditioningapparatus to transition to the end-of-life state of the refrigerantdetection unit 99.

When the refrigerant detection unit 99 comes to its end of life, thereis a risk of delay in detection of leakage of refrigerant when theleakage occurs due to the secular change in detection characteristics.Hence, after the transition to the end-of-life state of the refrigerantdetection unit 99, the controller 30 conducts the following control.That is, the controller 30 conducts control for outputting thenotification of an abnormality by a notifier (for example, display unitor audio output unit) provided in the operation unit 26. With thiscontrol, for example, the display unit displays textual informationindicating that the refrigerant detection unit 99 has come to its end oflife or that the refrigerant detection unit 99 is in an abnormal state.The display unit may display textual information for prompting the userto ask an expert service person for a repair (for example, replacementof the refrigerant detection unit 99).

Further, the controller 30 may conduct control for operating the indoorair-sending fan 7 f. With this control, when the indoor air-sending fan7 f is stopped, the operation of the indoor air-sending fan 7 f isstarted. When the indoor air-sending fan 7 f is already operating, theoperation is continued as it is.

Further, the controller 30 may conduct control for stopping thecompressor 3. With this control, when the compressor 3 is operating, thecompressor 3 is stopped, and when the compressor 3 is stopped, thestopped state of the compressor 3 is maintained. Further, the controller30 may conduct control for inhibiting restart of the operation of thecompressor 3.

In the end-of-life state of the refrigerant detection unit 99, when therefrigerant detection unit 99 is replaced with a new unit, thecontroller 30 causes the state of the air-conditioning apparatus totransition to the normal state (for example, normal state A). Forexample, the end-of-life state of the refrigerant detection unit 99transitions to the normal state only when the refrigerant detection unit99 is replaced with a new unit. That is, once the state of theair-conditioning apparatus transitions to the end-of-life state of therefrigerant detection unit 99, the state does not return to the normalstate unless the service person replaces the refrigerant detection unit99 with a new unit to remove the abnormality.

Further, in the first embodiment, methods of removing the abnormalityare limited to methods that can be conducted only by an expert serviceperson. This limitation can prevent the user from removing theabnormality irrespective of an unfinished replacement of the refrigerantdetection unit 99 with a new unit. Hence, the refrigerant detection unit99 whose detection characteristics have been changed can be preventedfrom being kept in continuous use, and the safety of theair-conditioning apparatus can be guaranteed. The methods of removingthe abnormality are limited to, for example, the following methods (1)to (4).

-   (1) Replacement of, for example, a control board of the controller    30-   (2) Use of a dedicated checker device-   (3) A special operation of the operation unit 26 (including a remote    controller)-   (4) An operation of the switch mounted on the control board of the    controller 30

To prevent the user from removing the abnormality, it is desired thatthe abnormality can be removed only by the methods (1) and (2), and itis further desired that the abnormality can be removed only by themethod (1).

The example of the configuration of the controller 30 that allowsremoval of the abnormality only by the above-mentioned method (1) isdescribed below. FIG. 7 is a block diagram for illustrating the exampleof the configuration of the controller 30. As illustrated in FIG. 7, thecontroller 30 includes, for example, an indoor unit controller 31mounted to the indoor unit 1 and configured to control the indoor unit1, an outdoor unit controller 32 mounted to the outdoor unit 2 andconfigured to control the outdoor unit 2, and an operation unitcontroller 33 mounted to the operation unit 26 and configured to controlthe operation unit 26. The operation unit 26 of the first embodiment isfixedly provided to the indoor unit 1, but the operation unit 26 may bea remote controller provided separately from the indoor unit 1 andcapable of remotely operating the air-conditioning apparatus.

The indoor unit controller 31 includes a control board 31 a and acontrol board 31 b capable of communicating with the control board 31 athrough a control line. The indoor unit controller 31 is configured tocommunicate with the outdoor unit controller 32 and the operation unitcontroller 33. A microcomputer 34 is mounted on the control board 31 a.A microcomputer 35 and the electric supply-type refrigerant detectionunit 99 are unremovably mounted on the control board 31 b. The electricsupply and the non-electric supply to the refrigerant detection unit 99are switched by the control conducted by the microcomputer 35. The timeof electric supply to the refrigerant detection unit 99 is integrated bythe microcomputer 35. The refrigerant detection unit 99 according to thefirst embodiment is directly mounted on the control board 31 b, but itsuffices that the refrigerant detection unit 99 is unremovably connectedto the control board 31 b. For example, the refrigerant detection unit99 may be provided in a position distant from the control board 31 b,and a wiring extending from the refrigerant detection unit 99 may beconnected to the control board 31 b by soldering or other ways. Further,in the first embodiment, the control board 31 b is provided separatelyfrom the control board 31 a, but the control board 31 b may be omitted,and the refrigerant detection unit 99 may be unremovably connected tothe control board 31 a.

The outdoor unit controller 32 includes a control board 32 a. Amicrocomputer 36 is mounted on the control board 32 a.

The operation unit controller 33 includes a control board 33 a. Amicrocomputer 37 is mounted on the control board 33 a.

The indoor unit controller 31 and the outdoor unit controller 32 arecommunicably connected to each other through a control line 38. Theindoor unit controller 31 and the operation unit controller 33 arecommunicably connected to each other through a control line 39.

The microcomputer 35 mounted on the control board 31 b includes arewritable nonvolatile memory (for example, flash memory). Thenonvolatile memory is provided with an abnormality history bit (exampleof an abnormality history storage area) for storing a history of theabnormality of the refrigerant detection unit 99. The abnormalityhistory bit of the microcomputer 35 can be set to “0” or “1”. Theabnormality history bit has an initial value of “0”. That is, in a caseof the microcomputer 35 in brand-new conditions or the microcomputer 35having no abnormality history, the abnormality history bit is set to“0”. The abnormality history bit of the microcomputer 35 is rewrittenfrom “0” to “1” when, for example, the integrated time of electricsupply to the refrigerant detection unit 99 becomes equal to or largerthan the threshold value H1. In other words, the abnormality history bitof the microcomputer 35 is set to “0” when the state of theair-conditioning apparatus is the normal state A or the normal state B,and the abnormality history bit of the microcomputer 35 is set to “1”when the state of the air-conditioning apparatus is the end-of-lifestate of the refrigerant detection unit 99. The abnormality history bitof the microcomputer 35 can be rewritten from “0” to “1” irreversiblyonly in one way. Further, the abnormality history bit of themicrocomputer 35 is maintained irrespective of whether or not electricpower is supplied to the microcomputer 35. The abnormality history bitmay be used only for storing whether or not the refrigerant detectionunit 99 has come to its end of life. In this case, the abnormalityhistory bit can be referred to as end-of-life bit, and the abnormalityhistory storage area can be referred to as end-of-life storage area.

Further, memories (nonvolatile memories or volatile memories) of themicrocomputers 34, 36, and 37 are each provided with the abnormalityhistory bit corresponding to the abnormality history bit of themicrocomputer 35. The abnormality history bits of the microcomputers 34,36, and 37 can be set to “0” or “1”, The abnormality history bits of themicrocomputers 34, 36, and 37 can be rewritten in both ways between “0”and “1”. The abnormality history bits of the microcomputers 34, 36, and37 have values set to the same value as that of the abnormality historybit of the microcomputer 35 acquired through communications. Even whenreturning to the initial value (for example, “0”) due to an interruptionof the electric power supply, the abnormality history bits of themicrocomputers 34, 36, and 37 are set to the same value as that of theabnormality history bit of the microcomputer 35 again when the electricpower supply is restarted.

When the abnormality history bit of the microcomputer 34 is set to “0”,the indoor unit controller 31 normally controls the indoor unit 1. Theindoor unit 1 in this state conducts and stops the operation in a normalstate in accordance with the operation through the operation unit 26.Meanwhile, when the abnormality history bit of the microcomputer 34 isset to “1”, the indoor unit controller 31 conducts control for causingthe notifier provided in the operation unit 26 to output thenotification of the abnormality. With this control, the display unit ofthe operation unit 26 displays, for example, textual informationindicating that the refrigerant detection unit 99 has come to its end oflife or that the refrigerant detection unit 99 is in an abnormal state,or textual information indicating measures to be taken by the user (forexample, contact to the service person). This display is maintained aslong as the abnormality history bit of the microcomputer 34 is set to“1”. Further, the indoor unit controller 31 conducts, for example,control for forcedly operating the indoor air-sending fan 7 f.

When the abnormality history bit of the microcomputer 36 is set to “0”,the outdoor unit controller 32 normally controls the outdoor unit 2.Meanwhile, when the abnormality history bit of the microcomputer 36 isset to “1”, the outdoor unit controller 32 conducts, for example,control for stopping the compressor 3. The stoppage of the compressor 3is continued as long as the abnormality history bit of the microcomputer36 is set to “1”.

When the abnormality history bit of the microcomputer 37 is set to “0”,the operation unit controller 33 normally controls the operation unit26. Meanwhile, when the abnormality history bit of the microcomputer 37is set to “1”, the operation unit controller 33 conducts control forcausing the display unit provided in the operation unit 26 to output thenotification of the abnormality. With this control, the display unit ofthe operation unit 26 displays, for example, textual informationindicating that the refrigerant detection unit 99 has come to its end oflife or that the refrigerant detection unit 99 is in an abnormal state,or textual information indicating measures to be taken by the user (forexample, contact to the service person). This display is maintained aslong as the abnormality history bit of the microcomputer 37 is set to“1”.

In such a configuration, when the integrated time of electric supply tothe refrigerant detection unit 99 becomes equal to or larger than thethreshold value H1, the microcomputer 35 rewrites the abnormalityhistory bit from the initial value “0” to “1” irreversibly. When theabnormality history bit of the microcomputer 35 is set to “1”, theabnormality history bits of the microcomputers 34, 36, and 37 are alsorewritten from “0” to “1”. With this control, the state of theair-conditioning apparatus transitions to the end-of-life state of therefrigerant detection unit 99, and the forced operation of the indoorair-sending fan 7 f, the stoppage of the compressor 3, the displaying ofthe information on the display unit of the operation unit 26, and otheroperations are conducted.

The service person contacted by the user replaces the refrigerantdetection unit 99 with a new unit. The refrigerant detection unit 99 isunremovably connected to the control board 31 b, and hence when therefrigerant detection unit 99 is replaced with a new unit, the controlboard 31 b is also replaced with a new board.

The abnormality history bit of the microcomputer 35 mounted on thereplaced control board 31 b is set to “0” that is the initial value.Hence, the abnormality history bits of the microcomputers 34, 36, and 37are also rewritten from “1” to “0”. Further, when the control board 31 bis replaced, the integrated time of electric supply is set to 0 that isthe initial value. This control allows the state of the air-conditioningapparatus to transition to the normal state to enable normal operationof the air-conditioning apparatus.

When the electric supply-type refrigerant detection unit 99 in theelectricity supplied state is exposed to a gas to be detected ormiscellaneous gases other than the gas to be detected for a long periodof time, the detection characteristics may be changed. In particular,when the refrigerant detection unit 99 is arranged in a high-temperatureenvironment, a high-humidity environment, or other environments, thedetection characteristics may be changed at increased speed. In view ofthis problem, in the first embodiment, the user is informed of theabnormality when the integrated time of electric supply to therefrigerant detection unit 99 becomes equal to or larger than thethreshold value H1. In this manner, the user can be prompted aboutreplacement of the refrigerant detection unit 99, and hence therefrigerant detection unit 99 whose detection characteristics have beenchanged can be prevented from being kept in continuous use.

Further, in the first embodiment, the electric supply to the refrigerantdetection unit 99 is stopped in the normal state B in which the rotationspeed of the indoor air-sending fan 7 f is equal to or larger than thethreshold value R1. As a result, the time of electric supply of therefrigerant detection unit 99 can be reduced, and hence the change indetection characteristics of the refrigerant detection unit 99 can bereduced. If the leakage of the refrigerant occurs in the normal state B,the leakage cannot be detected by the refrigerant detection unit 99.However, the indoor air-sending fan 7 f is rotated at a rotation speedthat is equal to or larger than the threshold value R1 in the normalstate B, and hence the leaked refrigerant can be diffused to the indoorspace.

Further, according to the first embodiment, the secular change of therefrigerant detection unit 99 can be reduced, and hence the detectioncharacteristics of the refrigerant detection unit 99 can be maintainedfor a long period of time. As a result, when the refrigerant leaks inthe normal state A, the leakage of the refrigerant can be detected morereliably, and hence the indoor air-sending fan 7 f can be operated morereliably. Further, the detection characteristics of the refrigerantdetection unit 99 can be maintained for a long period of time, and hencethe replacement frequency of the refrigerant detection unit 99 can bedecreased.

As described above, in the first embodiment, the indoor air-sending fan7 f can be reliably operated irrespective of whether the refrigerantleaks in the normal state A or the normal state B. Consequently,according to the first embodiment, even if the refrigerant leaks, therefrigerant concentration can be inhibited from being locally increased.As a result, even when, for example, a flammable refrigerant is used, itis possible to inhibit the flammable concentration region from beingformed in the indoor space.

In the first embodiment, the abnormality history bit that stores thepresence or absence of the abnormality history (for example, whether ornot the refrigerant detection unit 99 has come to its end of life) withone bit is exemplified as the abnormality history storage area providedto the nonvolatile memory, but the present invention is not limited tothis configuration. The nonvolatile memory may be provided with, forexample, the abnormality history storage area having two bits or more.The abnormality history storage area selectively stores any one of firstinformation indicating the state in which the refrigerant detection unit99 has not come to its end of life and second information indicating thestate in which the refrigerant detection unit 99 has come to its end oflife. Further, the information stored in the abnormality history storagearea can be changed from the first information to the second informationonly in one way. The indoor unit controller 31 is configured to changethe information stored in the abnormality history storage area from thefirst information to the second information when the integrated time ofelectric supply to the refrigerant detection unit 99 becomes equal to orlarger than the threshold value H1.

Second Embodiment

A refrigeration cycle apparatus according to a second embodiment of thepresent invention is described. In the second embodiment, anair-conditioning apparatus is exemplified as an example of therefrigeration cycle apparatus. The basic configuration of theair-conditioning apparatus according to the second embodiment is similarto that of the above-mentioned first embodiment, and hence a descriptionof the configuration is omitted. FIG. 8 is a graph for showing arelationship between the rotation speed of the indoor air-sending fan 7f and the air-conditioning apparatus state in the air-conditioningapparatus according to the second embodiment. In FIG. 8, the horizontalaxis represents the rotation speed of the indoor air-sending fan 7 f,and the vertical axis represents the state of the air-conditioningapparatus. As shown in FIG. 8, in the second embodiment, a differentialserving as a dead zone for control is set between the threshold value R1used for transition from the normal state B to the normal state A and athreshold value R2 used for transition from the normal state A to thenormal state B. In this case, the threshold value R2 is a value largerthan the threshold value R1 (R2>R1). The threshold value R1 and thethreshold value R2 are set, for example, within a rotation speed rangeof 0 or more and Rmax or less (0<R1<R2≤Rmax), preferably within arotation speed range of more than 0 and Rmax or less ((0<R1<R2≤Rmax),more preferably within a rotation speed range of more than Rmin and Rmaxor less (Rmin<R1<R2≤Rmax).

When the air-conditioning apparatus is in the normal state A, and therotation speed of the indoor air-sending fan 7 f becomes equal to orlarger than the threshold value R2, the air-conditioning apparatustransitions from the normal state A to the normal state B. Meanwhile,when the air-conditioning apparatus is in the normal state B, and therotation speed of the indoor air-sending fan 7 f becomes smaller thanthe threshold value R1, the air-conditioning apparatus transitions fromthe normal state B to the normal state A. The point that the refrigerantdetection unit 99 is supplied with electricity in the normal state A andthe electric supply to the refrigerant detection unit 99 is stopped inthe normal state B is similar to that in the above-mentioned firstembodiment.

In the above-mentioned first embodiment, when the indoor air-sending fan7 f is operated at a rotation speed close to the threshold value R1, theelectric supply and the non-electric supply to the refrigerant detectionunit 99 may be frequently switched. In contrast, in the secondembodiment, a differential is set between the threshold value R2 usedfor transition from the normal state A to the normal state B and thethreshold value R1 used for transition from the normal state B to thenormal state A. Consequently, according to the second embodiment, theelectric supply and the non-electric supply to the refrigerant detectionunit 99 can be prevented from being frequently switched.

As described above, the refrigeration cycle apparatus according to theabove-mentioned first and second embodiments includes the refrigerantcircuit 40 configured to circulate refrigerant, the indoor unit 1installed indoors and accommodating the load-side heat exchanger 7 ofthe refrigerant circuit 40, and the controller 30 configured to controlthe indoor unit 1. The indoor unit 1 includes the indoor air-sending fan7 f, the electric supply-type refrigerant detection unit 99, and thenotifier (for example, display unit or audio output unit provided in theoperation unit 26) configured to output the notification of theabnormality. The controller 30 is configured to stop electric supply tothe refrigerant detection unit 99 when an electric supply stop condition(for example, a condition in which the rotation speed of the indoorair-sending fan 7 f becomes equal to or larger than the threshold valueR1 or equal to or larger than the threshold value R2) is satisfied undera state in which the refrigerant detection unit 99 is supplied withelectricity, supply electricity to the refrigerant detection unit 99when an electric supply condition (for example, a condition in which therotation speed of the indoor air-sending fan 7 f becomes smaller thanthe threshold value R1) is satisfied under a state in which the electricsupply to the refrigerant detection unit 99 is stopped, and cause thenotifier to output the notification of the abnormality when theintegrated time of electric supply to the refrigerant detection unit 99becomes equal to or larger than a threshold time (for example, thresholdvalue H1).

According to this configuration, the user or others can be promptedabout replacement of the refrigerant detection unit 99 when theintegrated time of electric supply to the refrigerant detection unit 99becomes equal to or larger than the threshold value H1, and hence therefrigerant detection unit 99 whose detection characteristics have beenchanged can be prevented from being kept in continuous use.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the controller 30 may be configured to stopthe compressor 3 of the refrigerant circuit 40 when the integrated timeof electric supply becomes equal to or larger than the threshold valueH1.

When the integrated time of electric supply to the refrigerant detectionunit 99 becomes equal to or larger than the threshold value H1, there isa risk of delay in detection of leakage of refrigerant when the leakageoccurs due to the secular change of the detection characteristics of therefrigerant detection unit 99. According to the above-mentionedconfiguration, the compressor 3 of the refrigerant circuit 40 is stoppedwhen the integrated time of electric supply becomes equal to or largerthan the threshold value H1. Thus, the progress of the leakage can bereduced even when the leakage of the refrigerant occurs.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the controller 30 may be configured tooperate the indoor air-sending fan 7 f when the integrated time ofelectric supply becomes equal to or larger than the threshold value H1.

When the integrated time of electric supply to the refrigerant detectionunit 99 becomes equal to or larger than the threshold value H1, there isa risk of delay in detection of leakage of refrigerant when the leakageoccurs due to the secular change of the detection characteristics of therefrigerant detection unit 99. According to the above-mentionedconfiguration, the indoor air-sending fan 7 f is operated when theintegrated time of electric supply becomes equal to or larger than thethreshold value H1. Thus, the leaked refrigerant can be diffused evenwhen the leakage of the refrigerant occurs.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the electric supply stop condition may be acondition in which the rotation speed of the indoor air-sending fan 7 fbecomes equal to or larger than a first threshold rotation speed (forexample, threshold value R1 of the first embodiment or threshold valueR2 of the second embodiment), and the electric supply condition may be acondition in which the rotation speed of the indoor air-sending fanbecomes smaller than a second threshold rotation speed (for example,threshold value R1 of the first and second embodiments). The secondthreshold rotation speed may be equal to or smaller than the firstthreshold rotation speed.

According to this configuration, the time of electric supply of therefrigerant detection unit 99 can be reduced, and hence the secularchange in detection characteristics of the refrigerant detection unit 99can be reduced. Further, when the electric supply to the refrigerantdetection unit 99 is stopped, the indoor air-sending fan 7 f is rotatedat the first threshold rotation speed or more. Thus, even when therefrigerant leaks while the electric supply to the refrigerant detectionunit 99 is stopped, the leaked refrigerant can be diffused.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the controller 30 may include the controlboard 31 b to which the refrigerant detection unit 99 is unremovablyconnected, and the nonvolatile memory (for example, nonvolatile memoryincluded in the microcomputer 35) provided on the control board 31 b.The nonvolatile memory may be provided with an abnormality history bitthat can be set to “0” that is the initial value or “1”, and theabnormality history bit can be rewritten from “0” to “1” only in oneway. The controller 30 may be configured to rewrite the abnormalityhistory bit from “0” to “1” when the integrated time of electric supplybecomes equal to or larger than the threshold value H1.

According to this configuration, an abnormality history is written tothe nonvolatile memory of the control board 31 b irreversibly when theintegrated time of electric supply to the refrigerant detection unit 99becomes equal to or larger than the threshold value H1. To reset theabnormality history, the control board 31 b is required to be replacedwith another control board 31 b having no abnormality history. When thecontrol board 31 b is replaced, the refrigerant detection unit 99unremovably connected to the control board 31 b is also replaced. Hence,the refrigerant detection unit 99 whose detection characteristics havebeen changed can be prevented from being kept in continuous use.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the controller 30 may be configured tooperate the indoor air-sending fan 7 f when the controller 30 detectsleakage of the refrigerant on the basis of the detection signal from therefrigerant detection unit 99.

According to this configuration, the leaked refrigerant can be diffusedeven when the refrigerant leaks.

Third Embodiment

A refrigeration cycle apparatus according to a third embodiment of thepresent invention is described. In the third embodiment, anair-conditioning apparatus is exemplified as the refrigeration cycleapparatus. In the third embodiment, the integrated time of electricsupply has, in addition to the threshold value H1 (example of the firstthreshold time), a threshold value H2 (example of a second thresholdtime) that is smaller than the threshold value H1 (H1>H2). The thresholdvalues H1 and H2 are stored in advance in the ROM of the controller 30.

In the normal state (for example, normal state A or normal state B),when the integrated time of electric supply to the refrigerant detectionunit 99 is smaller than the threshold value H1 but becomes equal to orlarger than the threshold value H2, the controller 30 determines thatthe refrigerant detection unit 99 has come close to its end of life.That is, when the integrated time of electric supply to the refrigerantdetection unit 99 becomes equal to or larger than the threshold valueH2, the controller 30 causes the notifier provided in the operation unit26 to output the notification of information indicating that therefrigerant detection unit 99 has come close to its end of life orinformation for prompting the user to replace the refrigerant detectionunit 99 as an advance notice of the abnormality. In this manner, theuser can be prompted about replacement of the refrigerant detection unit99 before the refrigerant detection unit 99 comes to its end of life.For example, the threshold value H2 is set to a time of about 80% of thethreshold value H1. In this case, a time of about 20% of the thresholdvalue H1 is ensured from the notification of the advance notice of theend of life to the actual end of life of the refrigerant detection unit99. Hence, the user can have time for calling the service person forreplacement with a new unit before the refrigerant detection unit 99comes to its end of life.

The controller 30 is configured to select whether or not to cause thenotifier to output the notification of the advance notice of theabnormality as described above in accordance with the operation of theoperation unit. For example, the controller 30 selects whether or not tocause the notifier to output the notification of the advance notice ofthe end of life on the basis of the setting operation with a DIP switchprovided on the control board of the indoor unit controller or on thesetting operation with the operation unit 26. The setting operation withthe DIP switch or the setting operation with the operation unit 26 isperformed by, for example, the installation contractor or the serviceprovider of the air-conditioning apparatus.

For example, a user having a periodic maintenance contract with themaintenance provider (installing service provider) of theair-conditioning apparatus does not need to contact the maintenanceprovider for himself or herself to request replacement of therefrigerant detection unit 99. This is because, when the periodicmaintenance contract is concluded, the maintenance provider can conductactions of the replacement of the refrigerant detection unit 99 beforethe refrigerant detection unit 99 comes to its end of life on the basisof a customer inspection record (for example, operation history, failurehistory, and repair history from installation to present). That is, suchan air-conditioning apparatus is not necessarily required to output thenotification of the advance notice of the end of life of the refrigerantdetection unit 99. When the user is informed of information that theuser does not need to know through display (for example, characters orblinking light) or sound, the information may be an eyesore or anearsore for the user, and the user may feel discomfort. In the thirdembodiment, whether or not to cause the notifier to output thenotification of the advance notice of the end of life can be set, andhence the advance notice of the end of life by the notifier can beprevented from being an eyesore or an earsore for the user. Thus, theuser can be prevented from feeling unnecessary discomfort.

Fourth Embodiment

A refrigeration cycle apparatus according to a fourth embodiment of thepresent invention is described. In the fourth embodiment, anair-conditioning apparatus is exemplified as the refrigeration cycleapparatus. FIG. 9 is a diagram for schematically illustrating aconfiguration of the outdoor unit 2 of an air-conditioning apparatusaccording to the fourth embodiment. As already described above, theoutdoor unit 2 accommodates, for example, the compressor 3, therefrigerant flow switching device 4, the heat source-side heat exchanger5, the pressure reducing device 6, and the outdoor air-sending fan 5 f.Of these, the compressor 3 and the outdoor air-sending fan 5 f areillustrated in Fig, 9. The rotation speed of the outdoor air-sending fan5 f is controlled by the controller 30 to be variably set at multiplestages (for example, two stages or more) or continuously. The extensionpipes 10 a and 10 b are connected to the outdoor unit 2. The extensionpipes 10 a and 10 b and the refrigerant pipes inside the outdoor unit 2are connected to each other through joint portions 16 a and 16 b (forexample, flare joints). The joint portions 16 a and 16 b are arrangedinside the outdoor unit 2. The joint portions 16 a and 16 b may bearranged outside the outdoor unit 2.

The outdoor unit 2 (example of the heat exchanger unit) of the fourthembodiment includes a refrigerant detection unit 98. The refrigerantdetection unit 98 is arranged, for example, inside the outdoor unit 2and below the joint portions 16 a and 16 b. The refrigerant detectionunit 98 may be arranged below a brazed portion of the heat source-sideheat exchanger 5. As the refrigerant detection unit 98, an electricsupply gas sensor, for example, a semiconductor gas sensor or a hot-wiretype semiconductor gas sensor, is used. The refrigerant detection unit98 is configured to detect the refrigerant concentration in, forexample, the air around the refrigerant detection unit 98, and to outputthe detection signal to the controller 30. The controller 30 isconfigured to determine the presence or absence of the leakage of therefrigerant on the basis of the detection signal received from therefrigerant detection unit 98.

The refrigerant leakage detection processing of the fourth embodimentexecuted by the controller 30 is obtained by replacing the “refrigerantdetection unit 99” and the “indoor air-sending fan 7 f” of therefrigerant leakage detection processing of any one of the first andsecond embodiments described with reference to, for example, FIG. 5,FIG. 6, and FIG. 8, by the “refrigerant detection unit 98” and the“outdoor air-sending fan 5 f”, respectively. That is, in the refrigerantleakage detection processing of the fourth embodiment, when the leakageof the refrigerant is detected on the basis of the detection signalreceived from the refrigerant detection unit 98, an operation of theoutdoor air-sending fan 5 f is started. Consequently, the leakedrefrigerant can be diffused to an installation space of the outdoor unit2 (for example, outdoor space or machine room space). Hence, accordingto the fourth embodiment, even if the refrigerant leaks from the outdoorunit 2, it is possible to inhibit the refrigerant concentration in theinstallation space of the outdoor unit 2 from increasing locally.

Further, in the fourth embodiment, the electric supply to therefrigerant detection unit 98 is stopped in the normal state B in whichthe rotation speed of the outdoor air-sending fan 5 f is equal to orlarger than the threshold value R1. As a result, the time of electricsupply of the refrigerant detection unit 98 can be reduced, and hencethe change in detection characteristics of the refrigerant detectionunit 98 can be reduced. If the leakage of the refrigerant occurs in thenormal state B, the leakage cannot be detected by the refrigerantdetection unit 98. However, the outdoor air-sending fan 5 f is rotatedat a rotation speed that is equal to or larger than the threshold valueR1 in the normal state B, and hence the leaked refrigerant can bediffused to the installation space of the outdoor unit 2.

Further, in the fourth embodiment, when the integrated time of electricsupply to the refrigerant detection unit 98 becomes equal to or largerthan the threshold value H1, it is determined that the refrigerantdetection unit 98 has come to its end of life, and the notifier outputsthe notification of the abnormality. Hence, according to the fourthembodiment, the user or others can be prompted about replacement of therefrigerant detection unit 98, and hence the refrigerant detection unit98 whose detection characteristics have been changed can be preventedfrom being kept in continuous use.

Fifth Embodiment

A refrigeration cycle system according to a fifth embodiment of thepresent invention is described. FIG. 10 is a diagram for schematicallyillustrating an overall configuration of the refrigeration cycle systemaccording to the fifth embodiment. In the fifth embodiment, therefrigeration cycle apparatus included in the refrigeration cycle systemis exemplified by a separate type showcase. As illustrated in FIG. 10,the showcase includes an indoor unit 601 (example of the load unit andexample of the heat exchanger unit) installed in the indoor space, forexample, inside a shop, and an outdoor unit 602 (example of the heatsource unit and example of the heat exchanger unit) installed in, forexample, the machine room space. The indoor unit 601 and the outdoorunit 602 are connected to each other through the extension pipes 10 aand 10 b. The indoor unit 601 of the fifth embodiment does not includean air-sending fan configured to stir the air in the installation space.The outdoor unit 602 includes the outdoor air-sending fan 5 f.

Although not shown in FIG. 10, the controller 30 includes the indoorunit controller provided to the indoor unit 601 and the outdoor unitcontroller that is provided to the outdoor unit 602 and capable ofconducting communications with the indoor unit controller. The indoorunit controller and the outdoor unit controller are connected to eachother through a control line 603.

In the indoor space, an air-sending fan 604 configured to stir the airin the indoor space is provided separately from the showcase. Theair-sending fan 604 is provided outside the casing of the indoor unit601 of the showcase. The air-sending fan 604 can be operated, forexample, independently of the showcase. The air-sending fan 604 isconnected to the controller 30 (for example, indoor unit controller)through a control line (not shown). The rotation speed of theair-sending fan 604 is controlled by the controller 30 to be variablyset at multiple stages (for example, two stages or more) orcontinuously. When the refrigerant leaks into the indoor space, theair-sending fan 604 is operated to stir the air in the indoor spacetogether with leaked refrigerant. With this configuration, the leakedrefrigerant is diffused to the indoor space, and hence it is possible toinhibit the refrigerant concentration from increasing locally in theindoor space. That is, the air-sending fan 604 acts as a leakedrefrigerant dilution unit configured to dilute the refrigerant leakedinto the indoor space.

Further, in the indoor space, a refrigerant detection unit 605configured to detect the refrigerant is provided separately from theshowcase. The refrigerant detection unit 605 is provided outside thecasing of the indoor unit 601 of the showcase. The refrigerant has adensity larger than that of air under the atmospheric pressure, andhence the refrigerant detection unit 605 is provided, for example, closeto the floor surface in the indoor space. The refrigerant detection unit605 is connected to the controller 30 (for example, indoor unitcontroller) through a communication line 606. As the refrigerantdetection unit 605, an electric supply gas sensor, for example, asemiconductor gas sensor or a hot-wire type semiconductor gas sensor, isused. The refrigerant detection unit 605 is configured to detect therefrigerant concentration in the air around the refrigerant detectionunit 605, and to output the detection signal to the controller 30. Thecontroller 30 is configured to determine the presence or absence of theleakage of the refrigerant on the basis of the detection signal receivedfrom the refrigerant detection unit 605.

In the machine room space, an air-sending fan 607 for ventilation, whichis configured to deliver the air in the machine room space to theoutdoor space, is provided separately from the showcase. The air-sendingfan 607 is provided outside the casing of the outdoor unit 602 of theshowcase (for example, wall portion opposed to the outdoor space of themachine room space). The air-sending fan 607 can be operated, forexample, independently of the showcase. The air-sending fan 607 isconnected to the controller 30 (for example, outdoor unit controller)through a control line (not shown). The rotation speed of theair-sending fan 607 is controlled by the controller 30 to be variablyset at multiple stages (for example, two stages or more) orcontinuously. When the refrigerant leaks into the machine room space,the air-sending fan 607 is operated to deliver the air in the machineroom space to the outdoor space together with leaked refrigerant. Withthis configuration, the leaked refrigerant is delivered to the outdoorspace, and hence it is possible to inhibit the refrigerant concentrationfrom increasing locally in the machine room space. That is, theair-sending fan 607 acts as a leaked refrigerant dilution unitconfigured to dilute the refrigerant leaked into the machine room space.

Further, in the machine room space, a refrigerant detection unit 608configured to detect the refrigerant is provided separately from theshowcase. The refrigerant detection unit 608 is provided outside thecasing of the outdoor unit 602 of the showcase. The refrigerant has adensity larger than that of air under the atmospheric pressure, andhence the refrigerant detection unit 608 is provided, for example, closeto the floor surface in the machine room space. The refrigerantdetection unit 608 is connected to the controller 30 (for example,outdoor unit controller) through a communication line 609. As therefrigerant detection unit 608, an electric supply gas sensor, forexample, a semiconductor gas sensor or a hot-wire type semiconductor gassensor, is used. The refrigerant detection unit 608 is configured todetect the refrigerant concentration in the air around the refrigerantdetection unit 608, and to output the detection signal to the controller30. The controller 30 is configured to determine the presence or absenceof the leakage of the refrigerant on the basis of the detection signalreceived from the refrigerant detection unit 608.

FIG. 11 is a block diagram for illustrating a configuration of thecontroller 30 of the refrigeration cycle system according to the fifthembodiment. As illustrated in FIG. 11, the controller 30 includes anindoor unit controller 610 mounted to the indoor unit 601 and configuredto control the indoor unit 601, an outdoor unit controller 611 mountedto the outdoor unit 602 and configured to control the outdoor unit 602,and a remote controller control unit 612 mounted to the remotecontroller 27 (for example, operation unit provided in the indoor unit601) and configured to control the remote controller 27.

The indoor unit controller 610 is communicably connected to the outdoorunit controller 611 and the remote controller control unit 612 throughthe respective control lines. The indoor unit controller 610 includes acontrol board 610 a. A microcomputer 620 is mounted on the control board610 a.

The outdoor unit controller 611 includes a control board 611 a. Amicrocomputer 621 is mounted on the control board 611 a,

The remote controller control unit 612 includes a control board 612 a. Amicrocomputer 622 is mounted on the control board 612 a.

Further, an air-sending fan controller 613 configured to control theair-sending fan 604 is mounted to the air-sending fan 604 of the fifthembodiment. An air-sending fan controller 614 configured to control theair-sending fan 607 is mounted to the air-sending fan 607 of the fifthembodiment.

The air-sending fan controller 613 is communicably connected to theindoor unit controller 610 through the control line. The air-sending fancontroller 613 includes a control board 613 a. A microcomputer 623 ismounted on the control board 613 a.

The air-sending fan controller 614 is communicably connected to theoutdoor unit controller 611 through the control line. The air-sendingfan controller 614 includes a control board 614 a. A microcomputer 624is mounted on the control board 614 a.

Further, the controller 30 includes a sensor controller 615 configuredto control the refrigerant detection unit 605 and a sensor controller616 configured to control the refrigerant detection unit 608.

The sensor controller 615 is communicably connected to the indoor unitcontroller 610. The sensor controller 615 includes a control board 615a. A microcomputer 625 and the refrigerant detection unit 605 areunremovably mounted on the control board 615 a. The refrigerantdetection unit 605 of the fifth embodiment is directly mounted on thecontrol board 615 a, but it suffices that the refrigerant detection unit605 is unremovably connected to the control board 615 a. For example,the refrigerant detection unit 605 may be provided in a position distantfrom the control board 615 a, and a wiring extending from therefrigerant detection unit 605 may be connected to the control board 615a by soldering or other ways. Further, in the fifth embodiment, thecontrol board 615 a is provided separately from the control board 610 a,but the control board 615 a may be omitted, and the refrigerantdetection unit 605 may be unremovably connected to the control board 610a.

The sensor controller 616 is communicably connected to the outdoor unitcontroller 611. The sensor controller 616 includes a control board 616a. A microcomputer 626 and the refrigerant detection unit 608 areunremovably mounted on the control board 616 a. The refrigerantdetection unit 608 of the fifth embodiment is mounted directly on thecontrol board 616 a, but it suffices that the refrigerant detection unit608 is unremovably connected to the control board 616 a. For example,the refrigerant detection unit 608 may be provided in a position distantfrom the control board 616 a, and a wiring extending from therefrigerant detection unit 608 may be connected to the control board 616a by soldering or other ways. Further, in the fifth embodiment, thecontrol board 616 a is provided separately from the control board 611 a,but the control board 616 a may be omitted, and the refrigerantdetection unit 608 may be unremovably connected to the control board 611a.

The microcomputers 625 and 626 of the sensor controllers 615 and 616each include a rewritable nonvolatile memory. Each nonvolatile memory isprovided with a leakage history bit (one example of a leakage historystorage area) for storing a history of the refrigerant leakage. Theleakage history bit can be set to “0” or “1”, As the leakage historybit, “0” indicates a state of having no refrigerant leakage history, and“1” indicates a state of having a refrigerant leakage history. Theleakage history bit has an initial value of “0”. That is, in a case ofthe microcomputers 625 and 626 in brand-new conditions or themicrocomputers 625 and 626 having no refrigerant leakage history, theleakage history bit is set to “0”. The leakage history bit of themicrocomputer 625 is rewritten from “0” to “1” when the refrigerantdetection unit 605 detects the leakage of the refrigerant. When therefrigerant detection unit 608 detects the leakage of the refrigerant,the leakage history bit of the microcomputer 626 is rewritten from “0”to “1”. Both the leakage history bits of the microcomputers 625 and 626can be rewritten from “0” to “1” irreversibly only in one way. Further,the leakage history bits of the microcomputers 625 and 626 aremaintained irrespective of the presence or absence of electric powersupply to the microcomputers 625 and 626.

Memories of the microcomputers 620, 621, and 622 of the indoor unit 601,the outdoor unit 602, and the remote controller 27 are each providedwith a first leakage history bit corresponding to the leakage historybit of the microcomputer 625 and a second leakage history bitcorresponding to the leakage history bit of the microcomputer 626. Theseleakage history bits can be set to “0” or “1”, and can be rewritten inboth ways between “0” and “1”. The first leakage history bit of each ofthe microcomputers 620, 621, and 622 has a value set to the same valueas that of the leakage history bit of the microcomputer 625 acquiredthrough communications. The second leakage history bit of each of themicrocomputers 620, 621, and 622 has a value set to the same value asthat of the leakage history bit of the microcomputer 626 acquiredthrough communications. Even when returning to the initial value (forexample, “0”) due to an interruption of the electric power supply, thefirst leakage history bits and the second leakage history bits of themicrocomputers 620, 621, and 622 are set to the same value as these ofthe leakage history bits of the microcomputers 625 and 626 again whenthe electric power supply is restarted.

When both the first leakage history bit and the second leakage historybit of the microcomputer 620 are set to “0”, the indoor unit controller610 normally controls the indoor unit 601. The indoor unit 601 in thisstate conducts and stops the operation in a normal state in accordancewith the operation through the remote controller 27. When the firstleakage history bit of the microcomputer 620 is set to “1”, the indoorunit controller 610 conducts, for example, control for forcedlyoperating the air-sending fan 604 via the air-sending fan controller613.

When both the first leakage history bit and the second leakage historybit of the microcomputer 621 are set to “0”, the outdoor unit controller611 normally controls the outdoor unit 602. When the first leakagehistory bit or the second leakage history bit of the microcomputer 621is set to “1”, the outdoor unit controller 611 conducts, for example,control for stopping the compressor 3. The stoppage of the compressor 3is continued as long as the first leakage history bit or the secondleakage history bit of the microcomputer 621 is set to “1”. Further,when the second leakage history bit of the microcomputer 621 is set to“1”, the outdoor unit controller 611 conducts, for example, control forforcedly operating the air-sending fan 607 via the air-sending fancontroller 614. At this time, the outdoor unit controller 611 may alsoconduct control for forcedly operating the outdoor air-sending fan 5 f.

When both the first leakage history bit and the second leakage historybit of the microcomputer 622 are set to “0”, the remote controllercontrol unit 612 normally controls the remote controller 27. When thefirst leakage history bit or the second leakage history bit of themicrocomputer 622 is set to “1”, the remote controller control unit 612displays, for example, information including the abnormality type or theabnormality handling method on the display unit provided to the remotecontroller 27. At this time, the remote controller control unit 612 maydisplay information on the refrigerant leakage point on the display uniton the basis of which one of the first leakage history bit and thesecond leakage history bit is set to “1”. For example, when the firstleakage history bit is set to “1”, information indicating that theleakage of the refrigerant has occurred in the indoor unit 601 isdisplayed, and when the second leakage history bit is set to “1”,information indicating that the leakage of the refrigerant has occurredin the outdoor unit 602 is displayed. Further, the remote controllercontrol unit 612 may be configured to cause the audio output unitprovided to the remote controller 27 to output the notification on theabnormality type, the abnormality handling method, or the refrigerantleakage point by voice.

According to the fifth embodiment, the leakage history of therefrigerant is written to the nonvolatile memories of the control boards615 a and 616 a irreversibly. To reset the leakage history of therefrigerant, the control boards 615 a and 616 a need to be replaced byother control boards having no leakage history. When the control boards615 a and 616 a are replaced, the refrigerant detection units 605 and608 unremovably connected to the control boards 615 a and 616 a are alsoreplaced. Hence, the refrigerant detection units 605 and 608 exposed tothe refrigerant atmosphere to have changed detection characteristics canbe prevented from being kept in continuous use. Further, in the fifthembodiment, the operation of the showcase cannot be restarted unless thecontrol boards 615 a and 616 a are replaced, and hence the operation ofthe showcase that has not been repaired at the refrigerant leakage pointcan be prevented from being restarted due to a human error orintentionally.

Further, in the fifth embodiment, when the integrated time of electricsupply to the refrigerant detection unit 605 becomes equal to or largerthan the threshold value H1, it is determined that the refrigerantdetection unit 605 has come to its end of life, and the notifier outputsthe notification of the abnormality. Further, in the fifth embodiment,when the integrated time of electric supply to the refrigerant detectionunit 608 becomes equal to or larger than the threshold value H1, it isdetermined that the refrigerant detection unit 608 has come to its endof life, and the notifier outputs the notification of the abnormality.Hence, according to the fifth embodiment, the user or others can beprompted about replacement of the refrigerant detection units 605 and608, and hence the refrigerant detection units 605 and 608 whosedetection characteristics have been changed can be prevented from beingkept in continuous use.

In the fifth embodiment, only the memories of the microcomputers 620,621, and 622 of the indoor unit 601, the outdoor unit 602, and theremote controller 27 are provided with the first leakage history bit andthe second leakage history bit, but the memories of the microcomputers623 and 624 of the air-sending fans 604 and 607 may also be providedwith the first leakage history bit and the second leakage history bit.

Further, in the fifth embodiment, the air-sending fans 604 and 607include the air-sending fan controllers 613 and 614, respectively, andhence the air-sending fan 604 and the indoor unit 601 as well as theair-sending fan 607 and the outdoor unit 602 are connected to each otherthrough the respective control lines. However, the air-sending fans 604and 607 do not necessarily include the controller. When the air-sendingfans 604 and 607 do not include the controller, for example, theair-sending fan 604 and the indoor unit 601 as well as the air-sendingfan 607 and the outdoor unit 602 are connected to each other through apower supply line. In this case, the operation and stoppage of theair-sending fan 604 are controlled by a relay of the control board 610 aof the indoor unit controller 610, and the operation and stoppage of theair-sending fan 607 are controlled by a relay of a control board 611a ofthe outdoor unit controller 611.

Further, in the fifth embodiment, the leakage history bit, which storesthe presence or absence of the leakage history by 1 bit, is exemplifiedas the leakage history storage area provided to the nonvolatile memory,but the present invention is not limited to this configuration. Thenonvolatile memory may be provided with, for example, the leakagehistory storage area having equal to or larger than 2 bits. The leakagehistory storage area selectively stores any one of first informationindicating the state of having no refrigerant leakage history and secondinformation indicating the state of having a refrigerant leakagehistory. Further, the information stored in the leakage history storagearea can be changed from the first information to the second informationonly in one way. The controller 30 (for example, sensor controllers 615and 616) is configured to change the information stored in the leakagehistory storage area from the first information to the secondinformation when detecting the leakage of the refrigerant.

As described in the fifth embodiment, the refrigerant detection unit orthe air-sending fan is not necessarily built into the casing of theindoor unit or the outdoor unit of the refrigeration cycle apparatus.The refrigerant detection unit and the air-sending fan may be providedseparately from the refrigeration cycle apparatus as long as therefrigerant detection unit and the air-sending fan are communicablyconnected to the refrigeration cycle apparatus through the control lineor other ways, or are connected to the refrigeration cycle apparatus ina remotely controllable manner through the power supply line.

Further, as described in the fifth embodiment, when the refrigerantdetection unit and the air-sending fan are installed at each of theinstallation position of the indoor unit and the installation positionof the outdoor unit, only the air-sending fan in the space in which theleakage of the refrigerant is detected may be operated. That is, whenthe leakage of the refrigerant is detected by the refrigerant detectionunit provided at the installation position of the indoor unit, only theair-sending fan provided at the installation position of the indoor unitmay be operated. When the leakage of the refrigerant is detected by therefrigerant detection unit provided at the installation position of theoutdoor unit, only the air-sending fan provided at the installationposition of the outdoor unit may be operated.

Further, in the fifth embodiment, the air-sending fan 604 configured tostir the air in the indoor space is provided in the indoor space, andthe air-sending fan 607 for ventilation configured to deliver the air inthe machine room space to the outdoor space is provided in the machineroom space, but the present invention is not limited to thisconfiguration. For example, an air-sending fan for ventilationconfigured to deliver the air in the indoor space to the outdoor spacemay be provided in the indoor space, or an air-sending fan configured tostir the air in the machine room space may be provided in the machineroom space.

As described above, the refrigeration cycle apparatus according to theabove-mentioned embodiments includes the refrigerant circuit 40configured to circulate refrigerant, the heat exchanger unit (forexample, indoor unit 1 or outdoor unit 2) accommodating the heatexchanger (for example, load-side heat exchanger 7 or heat source-sideheat exchanger 5) of the refrigerant circuit 40, and the controller 30configured to control the heat exchanger unit. The heat exchanger unitincludes the air-sending fan (for example, indoor air-sending fan 7 f oroutdoor air-sending fan 5 f), the electric supply-type refrigerantdetection unit (for example, refrigerant detection unit 98 or 99), andthe notifier (for example, notifier provided in the operation unit 26)configured to output the notification of the abnormality. The controller30 is configured to stop electric supply to the refrigerant detectionunit when the electric supply stop condition is satisfied under thestate in which the refrigerant detection unit is supplied withelectricity, supply electricity to the refrigerant detection unit whenthe electric supply condition is satisfied under the state in which theelectric supply to the refrigerant detection unit is stopped, and causethe notifier to output the notification of the abnormality when theintegrated time of electric supply to the refrigerant detection unitbecomes equal to or larger than the threshold value H1.

According to this configuration, the user or others can be promptedabout replacement of the refrigerant detection unit when the integratedtime of electric supply to the refrigerant detection unit becomes equalto or larger than the threshold value H1, and hence the refrigerantdetection unit whose detection characteristics have been changed can beprevented from being kept in continuous use,

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the controller 30 may be configured to stopthe compressor 3 of the refrigerant circuit 40 when the integrated timeof electric supply becomes equal to or larger than the threshold valueH1.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the controller 30 may be configured tooperate the air-sending fan when the integrated time of electric supplybecomes equal to or larger than the threshold value H1 (for example,operate the indoor air-sending fan 7 f when the integrated time ofelectric supply to the refrigerant detection unit 99 becomes equal to orlarger than the threshold value H1, and operate the outdoor air-sendingfan 5 f when the integrated time of electric supply to the refrigerantdetection unit 98 becomes equal to or larger than the threshold valueH1).

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the electric supply stop condition may bethe condition in which the rotation speed of the air-sending fan becomesequal to or larger than the first threshold rotation speed (for example,threshold value R1 of the first embodiment or threshold value R2 of thesecond embodiment), and the electric supply condition may be thecondition in which the rotation speed of the air-sending fan becomessmaller than the second threshold rotation speed (for example, thresholdvalue R1 of the first and second embodiments). The second thresholdrotation speed may be equal to or smaller than the first thresholdrotation speed.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the controller 30 may be configured tooperate the air-sending fan when the controller 30 detects leakage ofthe refrigerant on the basis of the detection signal from therefrigerant detection unit.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the controller 30 may be configured tocause the notifier to output the notification of the advance notice ofthe abnormality when the integrated time of electric supply becomesequal to or larger than the second threshold time, which is smaller thanthe first threshold time.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the controller 30 may be configured toselect whether or not to cause the notifier to output the notificationof the advance notice of the abnormality.

Further, the refrigeration cycle apparatus according to theabove-mentioned embodiments includes the refrigerant circuit 40configured to circulate refrigerant, the heat exchanger unit (forexample, indoor unit 1 or outdoor unit 2) accommodating the heatexchanger of the refrigerant circuit 40, and the controller 30configured to control the heat exchanger unit. The heat exchanger unitincludes the electric supply-type refrigerant detection unit (forexample, refrigerant detection unit 98 or 99). The controller 30includes the control board 31 b to which the refrigerant detection unitis unremovably connected, and the nonvolatile memory (for example,nonvolatile memory included in the microcomputer 35) provided on thecontrol board 31 b. The nonvolatile memory is provided with theabnormality history storage area for storing any one of the firstinformation (for example, abnormality history bit (end-of-life bit) of“0”) indicating the state in which the refrigerant detection unit has noabnormality history (for example, the state in which the refrigerantdetection unit has not come to its end of life) and the secondinformation (for example, abnormality history bit (end-of-life bit) of“1”) indicating the state in which the refrigerant detection unit has anabnormality history (for example, the state in which the refrigerantdetection unit has come to its end of life). In the abnormality historystorage area, the first information is allowed to be changed to thesecond information only in one way. The controller 30 is configured tochange the information stored in the abnormality history storage areafrom the first information to the second information when the integratedtime of electric supply to the refrigerant detection unit becomes equalto or larger than the threshold value H1.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the second information may be informationindicating the end of life of the refrigerant detection unit.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the second information may be informationindicating the advance notice of the end of life of the refrigerantdetection unit.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the heat exchanger unit may further includethe notifier (for example, notifier provided in the operation unit 26),and the controller 30 may be configured to cause the notifier to outputthe notification of the abnormality when the information stored in theabnormality history storage area is changed to the second information.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the heat exchanger unit may further includethe notifier (for example, notifier provided in the operation unit 26),and the controller 30 may be configured to cause the notifier to outputthe notification of the abnormality when the information stored in theabnormality history storage area is changed to the second information.The controller 30 may be configured to select whether or not to causethe notifier to output the notification of the abnormality.

Further, in the refrigeration cycle apparatus according to theabove-mentioned embodiments, the heat exchanger may be the load-sideheat exchanger 7 or the heat source-side heat exchanger 5 of therefrigerant circuit 40.

Further, the refrigeration cycle system according to the above-mentionedembodiments includes the refrigeration cycle apparatus including therefrigerant circuit 40 configured to circulate refrigerant, thecontroller 30 configured to control the refrigerant circuit 40, and thenotifier (for example, notifier provided in the operation unit 26 ornotifier provided in the remote controller 27) configured to output thenotification of the abnormality, and the electric supply-typerefrigerant detection unit (for example, refrigerant detection unit 605or 608) configured to output a detection signal to the controller 30.The controller 30 is configured to stop electric supply to therefrigerant detection unit when the electric supply stop condition issatisfied under the state in which the refrigerant detection unit issupplied with electricity, supply electricity to the refrigerantdetection unit when the electric supply condition is satisfied under thestate in which the electric supply to the refrigerant detection unit isstopped, and cause the notifier to output the notification of theabnormality when the integrated time of electric supply to therefrigerant detection unit becomes equal to or larger than the thresholdvalue H1.

Further, the refrigeration cycle system according to the above-mentionedembodiments may further include the air-sending fan (for example,air-sending fan 604 or 607), in which the electric supply stop conditionmay be the condition in which the rotation speed of the air-sending fanbecomes equal to or larger than the first threshold rotation speed (forexample, threshold value R1 of the first embodiment or threshold valueR2 of the second embodiment), the electric supply condition may be thecondition in which the rotation speed of the air-sending fan becomessmaller than the second threshold rotation speed (for example, thresholdvalue R1 of the first and second embodiments), and the second thresholdrotation speed may be equal to or smaller than the first thresholdrotation speed.

Further, the refrigeration cycle system according to the above-mentionedembodiments may further include the air-sending fan (for example,air-sending fan 604 or 607), in which the controller 30 may beconfigured to operate the air-sending fan when the controller 30 detectsleakage of the refrigerant on the basis of the detection signal from therefrigerant detection unit.

Further, in the refrigeration cycle system according to theabove-mentioned embodiments, the controller 30 may be configured tocause the notifier to output the notification of the advance notice ofthe abnormality when the integrated time of electric supply becomesequal to or larger than the second threshold time, which is smaller thanthe first threshold time.

Further, in the refrigeration cycle system according to theabove-mentioned embodiments, the controller 30 may be configured toselect whether or not to cause the notifier to output the notificationof the advance notice of the abnormality.

Further, the refrigeration cycle system according to the above-mentionedembodiments includes the refrigeration cycle apparatus including therefrigerant circuit 40 configured to circulate refrigerant, and thecontroller 30 configured to control the refrigerant circuit 40, and theelectric supply-type refrigerant detection unit (for example,refrigerant detection unit 605 or 608) configured to output a detectionsignal to the controller 30. The controller 30 includes the controlboard (for example, control board 615 a or 616 a) to which therefrigerant detection unit is unremovably connected, and the nonvolatilememory (for example, nonvolatile memory included in the microcomputer625 or 626) provided on the control board. The nonvolatile memory isprovided with the abnormality history storage area for storing any oneof the first information (for example, abnormality history bit(end-of-life bit) of “0”) indicating the state in which the refrigerantdetection unit has no abnormality history (for example, the state inwhich the refrigerant detection unit has not come to its end of life)and the second information (for example, abnormality history bit(end-of-life bit) of “1”) indicating the state in which the refrigerantdetection unit has an abnormality history (for example, the state inwhich the refrigerant detection unit has come to its end of life). Inthe abnormality history storage area, the first information is allowedto be changed to the second information only in one way. The controller30 is configured to change the information stored in the abnormalityhistory storage area from the first information to the secondinformation when the integrated time of electric supply to therefrigerant detection unit becomes equal to or larger than the thresholdvalue H1.

Further, in the refrigeration cycle system according to theabove-mentioned embodiments, the second information may be informationindicating the end of life of the refrigerant detection unit.

Further, in the refrigeration cycle system according to theabove-mentioned embodiments, the second information may be informationindicating the advance notice of the end of life of the refrigerantdetection unit.

Further, in the refrigeration cycle system according to theabove-mentioned embodiments, the refrigeration cycle apparatus mayfurther include the heat exchanger unit (for example, indoor unit 1 oroutdoor unit 2) accommodating the heat exchanger of the refrigerantcircuit 40, and the heat exchanger unit may further include thenotifier. The controller 30 may be configured to cause the notifier tooutput the notification of the abnormality when the information storedin the abnormality history storage area is changed to the secondinformation.

Further, in the refrigeration cycle system according to theabove-mentioned embodiments, the refrigeration cycle apparatus mayfurther include the heat exchanger unit (for example, indoor unit 1 oroutdoor unit 2) accommodating the heat exchanger of the refrigerantcircuit 40, and the heat exchanger unit may further include thenotifier. The controller 30 may be configured to cause the notifier tooutput the notification of the abnormality when the information storedin the abnormality history storage area is changed to the secondinformation. The controller 30 may be configured to select whether ornot to cause the notifier to output the notification of the abnormality.

Other Embodiments

The present invention is not limited to the above-mentioned embodiments,and various modifications may be made to the embodiments.

For example, in the above-mentioned embodiments, the indoor unit 1 isexemplified by an indoor unit of a floor type, but the present inventioncan be applied to other indoor units of, for example, a ceiling-mountedcassette type, a ceiling-concealed type, a ceiling-suspended type, and awall-hung type.

Further, in the above-mentioned embodiments, the electric supply stopcondition is exemplified by the situation where the rotation speed ofthe indoor air-sending fan 7 f becomes equal to or larger than the firstthreshold rotation speed, and the electric supply condition isexemplified by the situation where the rotation speed of the indoorair-sending fan 7 f becomes smaller than the second threshold rotationspeed, but conditions other than the rotation speed of the indoorair-sending fan 7 f may be used as the electric supply stop conditionand the electric supply condition. During the normal operation of theindoor unit 1, there are a state in which the refrigerant detection unit99 is supplied with electricity and a state in which the electric supplyto the refrigerant detection unit is stopped.

Further, in the above-mentioned embodiments, the refrigeration cycleapparatus is exemplified by the air-conditioning apparatus. However, thepresent invention can also be applied to other refrigeration cycleapparatus such as a heat pump water heater.

Further, in the above-mentioned embodiments, the refrigerant detectionunit is exemplified by the semiconductor gas sensor and the hot-wiretype semiconductor gas sensor, but the present invention is not limitedto this configuration. As the refrigerant detection unit, for example,an infrared refrigerant detection unit or other refrigerant detectionunits can be used as long as the refrigerant detection unit is of anelectric supply type.

Further, the above-mentioned embodiments and modification examples maybe implemented in combinations,

REFERENCE SIGNS LIST

1 indoor unit 2 outdoor unit 3 compressor 4 refrigerant flow switchingdevice 5 heat source-side heat exchanger 5 f outdoor air-sending fan 6pressure reducing device 7 load-side heat exchanger 7 f indoorair-sending fan 9 a, 9 b indoor pipe 10 a, 10 b extension pipe 11suction pipe 12 discharge pipe 13 a, 13 b extension pipe connectingvalve 14 a, 14 b, 14 c service port 15 a, 15 b, 16 a, 16 b joint portion20 partition portion 20 a air passage opening part 25 electric componentbox 26

operation unit 27 remote controller 30 controller 31 indoor unitcontroller 31 a, 31 b control board 32 outdoor unit controller 32 acontrol board 33 operation unit controller 33 a control board 34, 35,36, 37

microcomputer 38, 39 control line 40 refrigerant circuit 81 air passage91 suction air temperature sensor 92 heat exchanger entrance temperaturesensor 93 heat exchanger temperature sensor 98, 99 refrigerant detectionunit 107 impeller 108 fan casing 108 a air outlet opening part 108 bsuction opening part 111 casing 112 air inlet 113 air outlet 114 a firstfront panel 114 b second front panel 114 c third front panel 115 a, 115b space 601 indoor unit 602 outdoor unit 603 control line 604

air-sending fan 605 refrigerant detection unit 606 communication line607 air-sending fan 608 refrigerant detection unit 609 communicationline 610 indoor unit controller 610 a control board 611 outdoor unitcontroller 611 a control board 612 remote controller control unit 612 a

control board 613, 614 air-sending fan controller 613 a, 614 a controlboard 615, 616 sensor controller 615 a, 616 a control board 620, 621,622, 623, 624, 625, 626 microcomputer

1. A refrigeration cycle apparatus, comprising: a refrigerant circuitconfigured to circulate refrigerant; a heat exchanger unit accommodatinga heat exchanger of the refrigerant circuit; and a controller configuredto control the heat exchanger unit, the heat exchanger unit including anair-sending fan, an electric refrigerant detection unit, and a notifierconfigured to output notification of an abnormality, the controller isconfigured to stop electric supply to the electric refrigerant detectionunit when an electric supply stop condition is satisfied under a statein which the electric refrigerant detection unit is supplied withelectricity, supply electricity to the electric refrigerant detectionunit when an electric supply condition is satisfied under a state inwhich the electric supply to the electric refrigerant detection unit isstopped, and cause the notifier to output the notification of theabnormality and operate the air-sending fan when an integrated time ofelectric supply to the electric refrigerant detection unit becomes equalto or larger than a first threshold time.
 2. The refrigeration cycleapparatus of claim 1, wherein the controller is configured to stop acompressor of the refrigerant circuit when the integrated time ofelectric supply becomes equal to or larger than the first thresholdtime. 3-4. (canceled)
 5. The refrigeration cycle apparatus of claim 1,wherein the controller is configured to operate the air-sending fan whenthe controller detects leakage of the refrigerant on a basis of adetection signal from the electric refrigerant detection unit.
 6. Therefrigeration cycle apparatus of claim 1, wherein the controller isconfigured to cause the notifier to output the notification of anadvance notice of the abnormality when the integrated time of electricsupply becomes equal to or larger than a second threshold time that issmaller than the first threshold time.
 7. The refrigeration cycleapparatus of claim 6, wherein the controller is configured to selectwhether or not to cause the notifier to output the notification of theadvance notice of the abnormality.
 8. The refrigeration cycle apparatusof claim 1, the controller including a control board to which theelectric refrigerant detection unit is unremovably connected, and anonvolatile memory provided on the control board, the nonvolatile memorybeing provided with an abnormality history storage area for storing anyone of first information indicating a state in which the electricrefrigerant detection unit has no abnormality history and secondinformation indicating a state in which the electric refrigerantdetection unit has an abnormality history, in the abnormality historystorage area, the first information is allowed to be changed to thesecond information only in one way, the controller being configured tochange the information stored in the abnormality history storage areafrom the first information to the second information when the integratedtime of electric supply becomes equal to or larger than the firstthreshold time or equal to or larger than a second threshold time thatis smaller than the first threshold time.
 9. The refrigeration cycleapparatus of claim 8, wherein the second information includesinformation indicating an end of life of the electric refrigerantdetection unit.
 10. The refrigeration cycle apparatus of claim 8,wherein the second information includes information indicating anadvance notice of an end of life of the electric refrigerant detectionunit.
 11. The refrigeration cycle apparatus of claim 8, wherein thecontroller is configured to cause the notifier to output thenotification of the abnormality when the information stored in theabnormality history storage area is changed to the second information.12. The refrigeration cycle apparatus of claim 10, wherein thecontroller is configured to cause the notifier to output thenotification of the abnormality when the information stored in theabnormality history storage area is changed to the second information,and the controller is configured to select whether or not to cause thenotifier to output the notification of the abnormality.
 13. Therefrigeration cycle apparatus of claim 1, wherein the heat exchangerincludes a load-side heat exchanger of the refrigerant circuit.
 14. Therefrigeration cycle apparatus of claim 1, wherein the heat exchangerincludes a heat source-side heat exchanger of the refrigerant circuit.15. A refrigeration cycle system, comprising: a refrigeration cycleapparatus including a refrigerant circuit configured to circulaterefrigerant, a controller configured to control the refrigerant circuit,and a notifier configured to output notification of abnormality anelectric refrigerant detection unit, the electric refrigerant detectionunit being configured to output a detection signal to the controller:and an air-sending fan, the controller being configured to stop electricsupply to the electric refrigerant detection unit when an electricsupply stop condition is satisfied under a state in which the electricrefrigerant detection unit is supplied with electricity, supplyelectricity to the electric refrigerant detection unit when an electricsupply condition is satisfied under a state in which the electric supplyto the electric refrigerant detection unit is stopped, and cause thenotifier to output the notification of the abnormality when anintegrated time of electric supply to the electric refrigerant detectionunit becomes equal to or larger than a first threshold time, theelectric supply stop condition including a condition in hick a rotationspeed of the air-sending fan becomes equal to or larger than a firstthreshold rotation speed, the electric supply condition including acondition in which the rotation speed of the air-sending fan becomessmaller than a second threshold rotation speed the second thresholdrotation speed being equal to or smaller than the first thresholdrotation speed. 16-17. (canceled)
 18. The refrigeration cycle system ofclaim 15, wherein the controller is configured to cause the notifier tooutput the notification of an advance notice of the abnormality when theintegrated time of electric supply becomes equal to or larger than asecond threshold time that is smaller than the first threshold time. 19.The refrigeration cycle system of claim 18, wherein the controller isconfigured to select whether or not to cause the notifier to output thenotification of the advance notice of the abnormality.
 20. Therefrigeration cycle system of claim 15, the controller including acontrol board to which the electric refrigerant detection unit isunremovably connected, and a nonvolatile memory provided on the controlboard, the nonvolatile memory being provided with an abnormality historystorage area for storing any one of first information indicating a statein which the electric refrigerant detection unit has no abnormalityhistory and second information indicating a state in which the electricrefrigerant detection unit has an abnormality history, in theabnormality history storage area, the first information is allowed to bechanged to the second information only in one way, the controller beingconfigured to change the information stored in the abnormality historystorage area from the first information to the second information whenthe integrated time of electric supply becomes equal to or larger thanthe first threshold time or equal to or larger than a second thresholdtime that is smaller than the first threshold time.
 21. Therefrigeration cycle system of claim 20, wherein the second informationincludes information indicating an end of life of the electricrefrigerant detection unit.
 22. The refrigeration cycle system of claim20 wherein the second information includes information indicating anadvance notice of an end of life of the electric refrigerant detectionunit.
 23. The refrigeration cycle system of claim 20, wherein thecontroller is configured to cause the notifier to output thenotification of the abnormality when the information stored in theabnormality history storage area is changed to the second information.24. The refrigeration cycle system of claim 22, wherein the controlleris configured to cause the notifier to output the notification of theabnormality when the information stored in the abnormality historystorage area is changed to the second information; and. the controlleris configured to select whether or not to cause the notifier to outputthe notification of the abnormality.
 25. A refrigeration cycleapparatus, comprising: a refrigerant circuit configured to circulaterefrigerant; a heat exchanger unit accommodating a heat exchanger of therefrigerant circuit; and a controller configured to control the heatexchanger unit, the heat exchanger unit including an air-sending fan, anelectric refrigerant detection unit, and a notifier configured to outputnotification of an abnormality, the controller is configured to stopelectric supply to the electric refrigerant detection unit when anelectric supply stop condition is satisfied under a state in which theelectric refrigerant detection unit is supplied with electricity, supplyelectricity to the electric refrigerant detection unit when an electricsupply condition is satisfied under a state in which the electric supplyto the electric refrigerant detection unit is stopped, and cause thenotifier to output the notification of the abnormality when anintegrated time of electric supply to the electric refrigerant detectionunit becomes equal to or larger than a first threshold time, theelectric supply stop condition including a condition in which a rotationspeed of the air-sending fan becomes equal to or larger than a firstthreshold rotation speed, the electric supply condition including acondition in which the rotation speed of the air-sending fan becomessmaller than a second threshold rotation speed, the second thresholdrotation speed being equal to or smaller than the first thresholdrotation speed.
 26. The refrigeration cycle apparatus of claim 1,wherein the notification of the abnormality comprising notificationprompting replacement of the electric refrigerant detection unit.
 27. Arefrigeration cycle apparatus, comprising: a refrigerant circuitconfigured to circulate refrigerant; a heat exchanger unit accommodatinga heat exchanger of the refrigerant circuit; and a controller configuredto control the heat exchanger unit, the heat exchanger unit including anair-sending fan, and an electric refrigerant detection unit, thecontroller being configured to operate the air-sending fan when thecontroller detects leakage of the refrigerant on a basis of a detectionsignal from the electric refrigerant detection unit, the controller isconfigured to stop electric supply to the electric refrigerant detectionunit when a rotation speed of the air-sending fan becomes equal to orlarger than a first threshold rotation speed under a state in which theelectric refrigerant detection unit is supplied with electricity. 28.The refrigeration cycle apparatus of claim 27, wherein the controller isconfigured to supply electricity to the electric refrigerant detectionunit when the rotation speed of the air-sending fan becomes smaller thana second threshold rotation speed under a state in which the electricsupply to the electric refrigerant detection unit is stopped, and thesecond threshold rotation speed is equal to or smaller than the firstthreshold rotation speed.
 29. A refrigeration cycle system, comprising:a refrigeration cycle apparatus including a refrigerant circuitconfigured to circulate refrigerant, a controller configured to controlthe refrigerant circuit, and a notifier configured to outputnotification of an abnormality; an electric refrigerant detection unit,the electric refrigerant detection unit being configured to output adetection signal to the controller; and an air-sending⁻ fan, thecontroller being configured to stop electric supply to the electricrefrigerant detection unit when an electric supply stop condition issatisfied under a state in which the electric refrigerant detection unitis supplied with electricity, supply electricity to the electricrefrigerant detection unit when an electric supply condition issatisfied under a state in which the electric supply to the electricrefrigerant detection unit is stopped, and cause the notifier to outputthe notification of the abnormality when an integrated time of electricsupply to the electric refrigerant detection unit becomes equal to orlarger than a first threshold time, the controller being configured tooperate the air-sending fan when the controller detects leakage of therefrigerant on a basis of the detection signal from the electricrefrigerant detection unit.
 30. The refrigeration cycle system of claim15, wherein the notification of the abnormality comprising notificationprompting replacement of the electric refrigerant detection unit.
 31. Arefrigeration cycle system,o a refrigeration cycle apparatus including arefrigerant circuit configured to circulate refrigerant, and acontroller configured to control the refrigerant circuit; an air-sendingfan configured to be controlled by the controller; and an electricrefrigerant detection unit, the electric refrigerant detection unitbeing configured to output a detection signal to the controller, thecontroller being configured to operate the air-sending fan when thecontroller detects leakage of the refrigerant on a basis of thedetection signal from the electric refrigerant detection unit, thecontroller being configured to stop electric supply to the electricrefrigerant detection unit when a rotation speed of the air-sending fanbecomes equal to or larger than a first threshold rotation speed under astate in which the electric refrigerant detection unit is supplied withelectricity.
 32. The refrigeration cycle system of claim 31, wherein thecontroller is configured to supply electricity to the electricrefrigerant detection unit when the rotation speed of the air-sendingfan becomes smaller than a second threshold rotation speed under a statein which the electric supply to the electric refrigerant detection unitis stopped, and the second threshold rotation speed is equal to orsmaller than the first threshold rotation speed.